r^  (Library  of 


NATURE    STOOD*; 


FOR 


THE   COMMON  SCHOOLS 


BY 

WILBUR  S.  JACKMAN,  A.  B. 

TEACHER   OF  NATURAL  SCIENCE,    COOK   COUNTY   NORMAL    SCHOOL, 
CHICAGO,    ILL. 

SECOND  EDITION  RE  VISED. 


NEW  YORK 

HENRY    HOLT    AND    COMPANY 
1892 


£ 

\y 


COPYRIGHT,  1891, 

BY 

WILBUR  S.  JACKMAN. 

EDUCATION 


THE   MERSHON    COMPANY   PRESS, 
RAHWAY,    N.   J. 


<&jcrmroxrtt  Jjctxxrxrl 

THIS    BOOK    IS    RESPECTFULLY    DEDICATED    BY 

THE  AUTHOR. 


54.)  226 


PREFACE. 


In  the  preparation  of  this  book  it  has  been  the  aim 
to  furnish  a  guide  for  teachers  in  the  common  schools 
who  wish  their  pupils  to  pursue  an  adequate  and  sym- 
metrical course  in  Natural  Science.  Science  teaching  for 
a  few  years  past  has  been  gradually  working  itself  down- 
ward from  the  colleges  and  high  schools  into  those  of 
lower  grades,  but,  in  most  cases,  the  plans  followed, 
while  fairly  well  adapted  to  the  demands  of  advanced 
pupils,  have  been  but  poorly  fitted  to  the  needs  of  begin- 
ners. The  plan  here  adopted  is  based  upon  what  is  be- 
lieved to  be  the  proper  interpretation  of  the  character  of 
the  knowledge  that  the  child  can  acquire.  This  knowl- 
edge may  be  characterized  as  having  great  breadth  but 
little  depth.  The  forces  of  nature  impinge  upon  the 
child  from  every  side,  and  he  responds  at  once  to  their 
touch.  Animal,  plant,  mineral,  river,  cloud,  sunbeam, 
mountain,  physical  and  chemical  changes  are  all  matters 
of  equal  and  absorbing  interest  to  him,  and  if  left  to 
himself  he  will  inquire  as  freely  about  one  as  another. 
It  is  a  mistaken  idea  that  the  child's  interest  is  best 
aroused  by  a  "  thorough  "  study  of  a  few  living  things, 
animal  or  plant,  such  as  form  the  chief  stock  in  trade  in 
many  school-rooms.  This  specialization  in  elementary 
grades  must  result  in  one  or  both  of  two  things  :  either 
the  whole  subject  will  become  distasteful,  or,  at  least, 


IV 


PREFACE. 


tiresome  to  the  pupil,  or  his  eyes  will  be  closed  to  other 
sides  of  nature  equally  interesting  and  important.  In 
either  case  the  subject  studied  will  be  but  poorly  under- 
stood, because  it  has  been  isolated  and  its  relations  to 
other  subjects  not  clearly  seen.  An  attempt  has  here 
been  made  to  get  rid  of  the  old  linear  arrangement  of 
the  different  divisions  of  natural  science  in  a  course  of 
study  in  which  the  various  subjects  were  made  to  follow 
one  another  in  an  unnatural  sequence. 

The  Unity  of  Science,  with  Life  the  central  study,  is  the 
basal  idea  upon  which  the  work  has  been  prepared. 
Life,  in  the  final  analysis  the  individual's  own  life,  is  the 
center  of  all  study,  and  the  value  of  any  particular  sub- 
ject must  be  ultimately  estimated  by  what  it  contributes 
toward  a  better  comprehension  of  it.  This  idea  is  em- 
bodied in  the  appended  synopsis  of  the  entire  subject. 


' 

ENERGY 

LIFE 
and  its 
PHENOMENA, 

An 
Expression 

° 

8 

acting    \ 
through  ^ 

[ 

MATTER 

ANIMAL  c 

r   Zoology  | 
^-Biology. 
Botrmy   ) 

•o 

Physics. 

$ 

J:  ° 
a^ 

Chemistry. 

s  - 

and        £  '^  J,    Meteorology. 

1 

I"! 

C/5 

Astronomy. 
Geography. 

X 

PLANT    r 

Geology. 
Mineralogy. 

It  is  not  intended  that  the  Science  work  outlined  in  the 
following  pages  should  be  incidental,  as  ordinarily  under- 
stood, but  that  it  shall  be  assigned  a  regular  place  in  the 
daily  programme  with  other  lessons.  Regularity  and  fre- 
quency of  the  exercises  are  of  primary  importance,  while 
the  absolute  amount  of  time  devoted  to  them  is  secondary. 
For  a  scheme  of  twenty  exercises  fora  month  the  follow- 


PREFACE.  V 

ing  division  of  the  work  is  suggested  :  Zoology  and 
Botany,  one  lesson  each  week  ;  Physics,  Meteorology, 
Astronomy,  Geography,  and  Geology,  one  lesson  each  in 
two  weeks  ;  Chemistry  and  Mineralogy,  one  lesson  each 
a  month.  This  order  and  division  should  be  modified  so 
as  to  suit  the  character  of  the  season,  the  grade,  and  the 
various  minor  conditions  peculiar  to  the  circumstances  of 
the  different  teachers.  By  "lessons  "  it  is  meant  that  at 
regular  times  in  general  exercises  the  results  of  the  pupils' 
observations  will  be  gathered  up  and  discussed  and  sys- 
tematically arranged,  and  that  at  such  times  general  ex- 
periments may  be  performed  or  other  observatious  made. 

It  may  be  thought  that  the  results  thus  obtained  will 
be  disconnected  and  superficial  ;  but  many  thoughtful 
teachers  who  have  tried  the  plan  find  the  reverse  to  be 
true,  and  that  the  reasoning  powers  of  the  pupils  are 
greatly  quickened  by  their  having  at  hand  a  large  amount 
of  data  gathered  in  a  varied  experience.  If  the  one  les- 
son be  of  a.  fruitful^  stimulating  character,  the  pupils  will 
be  observant  and  thoughtful  until  the  time  for  the  next 
one  arrives,  which  is  all  that  is  necessary  to  secure  a 
healthy  mind  development. 

The  work  assigned  to  each  month  has  been  selected 
because  it  will  be  most  natural  for  the  pupils  in  its  proper 
season,  and  in  many  cases  it  can  be  better  understood, 
and  because  at  such  times  it  is  most  convenient  for  the 
teacher  to  secure  appropriate  material  and  conditions. 
The  division  into  different  subjects  is  for  the  teacher's 
convenience  alone,  it  not  being  necessary  for  the  pupils 
to  know  even  the  approximate  limitations  of  the  subjects 
between  which  hard  and  fast  lines  do  not  exist. 

It  must  not  for  a  moment  be  supposed  that  it  is  the 
design  for  the  teacher  and  pupils  to  finish  the  outlines 


VI  PREFACE. 

prepared  for  any  month  or  season.  Science  cannot  be 
finished  in  a  month,  nor  in  a  lifetime,  though  the  study  of 
it  is  too  often  most  unfortunately  finished  by  those  teach- 
ers who  put  an  end  to  their  pupils'  desire  to  know 
more  about  it.  Certain  lines  have  here  been  indicated, 
along  which  it  is  hoped  that  teachers  may  be  able  to 
awaken  and  foster  observation  and  thought,  and  at  the 
same  time  bring  their  pupils  into  fuller  knowledge  of 
themselves  and  of  their  duties  and  relations  to  the  world 
around  them. 

The  author  desires  to  acknowledge  his  indebtedness  for 
much  that  is  contained  in  the  chapter  on  Expression  to 
the  discussions  which,  under  the  leadership  of  Colonel 
F.  W.  Parker,  have  made  the  ever-to-be-remembered 
Monday  evening  Faculty  meetings  an  unfailing  source  of 
inspiration  in  all  the  work. 

W.  S.  J. 

COOK  COUNTY  NORMAL  SCHOOL, 

CHICAGO,  ILL.,  July  i,  1891. 


CONTENTS 


PAGE 

PREFACE,          ,  m-vi 

CHAPTER  I.     INTRODUCTORY:  THE  MOTIVE,  .  1-7 

CHAPTER  II.     PRINCIPLES,       .......  8-12 

CHAPTER  III.     EXPRESSION,    ......  13-25 

CHAPTER  IV.     PRACTICAL  HINTS  TO  THE  TEACHER,     .  26-28 

WORK  FOR  SEPTEMBER. 

ZOOLOGY: — Birds.  Insects.  Worms.  Tadpoles.  BOTANY: 
—Fruits— Seeds.  PHYSICS:— Light.  Magnetism.  CHEM- 
ISTRY:—Fermentation.  METEOROLOGY:— General  Direc- 
tions and  Suggestions.  Study  of  Signal  Service  Maps. 
Charts  I  to  VII.  ASTRONOMY: — General  Directions. 
Equinox.  Constellations.  GEOGRAPHY: — Direction.  Lati- 
tude and  Longitude.  North  America. — Position.  GEOLOGY: 
— Study  of  Immediate  Vicinity.  MINERALOGY: — Physical 
Properties  of  Minerals.  Mineralogical  Record.  Synopti- 
cal Key  for  Analysis,  .  29-74 

WORK  FOR  OCTOBER. 

ZOOLOGY: — General  Observations.  A  Study  of  Tissues. 
The  Muscle.  Connective  Tissue.  The  Bone — Osseous 
Tissue.  Fat — Adipose  Tissue.  The  Joint.  BOTANY: 
— Fall  of  Leaf.  Distribution  of  Seeds.  PHYSICS: — Evap- 
oration. Ebullition.  Condensation.  Distillation.  CHEM- 
ISTRY:— Solution.  Crystallization.  METEOROLOGY: — Study 
of  Signal  Service  Maps.  ASTRONOMY: — Change  of  Noon 
Shadow.  Full  Moon.  GEOGRAPHY: — Drainage — General 
Conditions.  North  America.  GEOLOGY: — Erosion  and 
Sedimentation.  MINERALOGY: — Study  of  Sand,  .  75-97 


Vlll  CONTENTS. 

WORK  FOR  NOVEMBER 

PAGE 

ZOOLOGY: — General  Observations.  Animal  Coverings  and 
Warmth.  The  Skin  of  the  Human  Body.  BOTANY: — 
Effects  of  Frost.  Classes  of  Plants.  PHYSICS: — Heat — 
Radiation — Absorption — Reflection.  Temperature.  Ex- 
pansion— of  Solids— of  Liquids— of  Gases.  CHEMISTRY;. 
—Chemical  Change.  METEOROLOGY: — Frost,  etc.  Study 
of  Signal  Service  Maps.  ASTRONOMY:— Variation  of 
Length  of  Day.  Seasons.  GEOGRAPHY:— Climate  of 
North  America.  Drai  lage  of  South  America.  GEOLOGY: 
— Pebbles.  MINERALOGY:— Specific  Gravity.  Study  of 
Coal, 98-134 

WORK  FOR  DECEMBER. 

ZOOLOGY: — General  Observations.  Animal  Movements. 
The  Skeleton.  BOTANY: — Effects  of  Freezing.  PHYSICS: 
— The  Lever.  Equilibrium  of  Bodies.  Heat — Liquefac- 
faction — Conduction — Convection.  Capacity  for  Heat. 
Sources.  CHEMISTRY  : — Oxygen — Preparation — Experi- 
ments. METEOROLOGY: — Rainfall.  Study  of  Signal  Ser- 
vice Maps.  ASTRONOMY: — Winter  Solstice.  GEOGRA- 
PHY:—North  America— Soil  and  Productions.  Minerals. 
South  America— Climate.  GEOLOGY:— Atmospheric  and 
Aqueous  Agencies.  MINERALOGY: — Iron  Ore.  Iron,  135-179 

WORK  FOR  JANUARY. 

ZOOLOGY:  —  General  Observations.  Foods— Different 
Kinds.  Cooking.  Hunger  and  Appetite.  BOTANY: — Effects 
of  Freezing.  PHYSICS: — Air— Elasticity — Pressure.  The 
Pendulum.  CHEMISTRY: — Hydrogen — Preparation  and 
Experiments.  METEOROLOGY: — Temperature.  Study  of 
Signal  Service  Maps.  ASTRONOMY: — Rate  of  Change  in 
Length  of  Day.  Venus.  GEOGRAPHY: — South  America — 
Productions.  GEOLOGY :— Fossil  Plants.  MINERALOGY: 
—Acid  Tests, 180-220 

WORK  FOR  FEBRUARY. 

ZOOLOGY: — General  Observations.  Prehension  of  Food 
Mastication  of  Food  Insalivation  and  Swallowing. 


CONTENTS.  ix 

PACK 

BOTANY: — Winter  Condition  of  Plants,  Pines.  PHYSICS: 
— Air — The  Pump — The  Siphon.  Capillarity.  Buoyancy 
of  Liquids  Pressure  of  Liquids.  CHEMISTRY: — Carbon. 
METEOROLOGY: — Snowfall.  Study  of  Signal  Service 
Maps.  ASTRONOMY:— Planets.  Constellations.  GEOGRA- 
PHY:— Euro- Asia  —  Relief  and  Drainage.  GEOLOGY: — 
Fossil  Animals.  MINERALOGY: — Calcination,  .  221-258 

WORK  FOR  MARCH. 

ZOOLOGY: — Natural  History  Calendar.  General  Observa- 
tions. The  Circulation.  BOTANY: — Tree  Selected*  for 
Special  Study.  PHYSICS: — Light.  Images.  Mirrors. 
CHEMISTRY: — Nitrogen.  Air.  METEOROLOGY: — Extremes 
in  Weather.  Study  of  Signal  Service  Maps.  ASTRON- 
OMY*— Vernal  Equinox.  Jupiter.  Position  of  Planets. 
GEOGRAPHY  :  —Euro-Asia—Climate.  GEOLOGY  : — Organic 
Agencies.  MINERALOGY:— Forms  of  Stones,  .  259-302 

WORK  FOR  APRIL. 

ZOOLOGY: — General  Observations.  Birds.  Insects.  Pond 
Life.  Respiration.  BOTANY: — Germination.  A  Seed. 
Development  of  Buds.  Classification  of  Buds  as  to  Posi- 
tion, Activity,  Covering,  Arrangement.  Underground 
Forms  of  the  Plant  Axis.  PHYSICS: — Light —Refraction. 
Lenses.  CHEMISTRY: — Water.  METEOROLOGY: — Influ- 
ences of  the  Month.  Study  of  Signal  Service  Maps. 
ASTRONOMY:  —  Function  of  Symbols.  Constellations. 
GEOGRAPHY : — Euro-Asia — Productions.  GEOLOGY  : — Study 
of  a  Swamp.  MINERALOGY: — Flame  Tests,  .  .  303-344 

WORK  FOR  MAY. 

ZOOLOGY:— Cruelty  to  Animals.  Robbing  Birds'  Nests. 
Preservation  of  Nests  and  Eggs.  Birds'  Nests  and  Eggs. 
Parts  of  an  Egg,  and  the  Embryo.  The  Crawfish,  Seeing. 
BOTANY:— Use  of  Botanical  Key.  How  to  Study  Flowers. 
The  Flower.  Inflorescence.  Buds.  Ferns.  Mossest 
PHYSICS: — Sound.  CHEMISTRY:— Flame.  METEOROLOGY: 
— Influences  of  the  Month.  Study  of  the  Signal  Service 


X  CONTENTS. 

PAGft 

Maps.  ASTRONOMY: — Rate  of  Change  in  Length  of  Day 
and  Night.  Twilight.  GEOGRAPHY: — Africa — Relief — 
Drainage — Climate  and  Productions.  GEOLOGY: — Field 
Lessons.  MINERALOGY: — Examination  of  Soils— Physical 
Constituents,  .......  345~393 

WORK  FOR  JUNE. 

ZOOLOGY:— General  Remarks.  Birds.  Insects — Bees — Ants 
—Spiders — The  House-fly  —  Beetles.  Reptiles  —  Snakes 
— Turtles.  BOTANY:— Plant  Physiology.  Water  Culture. 
Plant  Constituents.  Leaves.  Growth  of  Stem.  The 
Grasses.  PHYSICS: — Electricity.  Magnetism  and  Fric- 
tional  Electricity.  Voltaic  Electricity.  CHEMISTRY: — 
Chlorine.  METEOROLOGY:— Thunder-storms.  Tempera- 
ture. Study  of  Signal  Service  Maps.  ASTRONOMY: — Im- 
portance of  Searching  for  Causes.  Summer  Solstice. 
GEOGRAPHY: — Winds.  Ocean  Currents.  GEOLOGY: — 
Springs  and  Wells.  MINERALOGY: — Physical  Properties 
of  Soils,  ........  394-438 

INDEX          .  439~448 


NATURE  STUDY 
FOR  THE  COMMON  SCHOOLS. 


INTRODUCTORY. 
CHAPTER  I. 

THE    MOTIVE. 

IT  is  of  primary  importance  that  the  teacher  who 
seeks  to  introduce  elementary  science  into  the  common 
schools  should  make  earnest  study  of  the  motive  for  do- 
ing such  work,  and  at  the  same  time  carefully  formulate 
intelligent  methods  for  conducting  it.  It  is  under  no 
other  conditions  that  the  undertaking  can  be  successfully 
carried  out,  and,  rather  than  attempt  to  do  it  blindly, 
the  task  had  better  not  be  begun. 

Natural  science,  concerned  largely  with  the  earth  and 
the  living  things  it  supports,  affords  the  earliest  and  the 
only  direct  means  of  introducing  the  child  to  his  earthly 
habitation.  The  life,  health,  and  happiness  of  the  in- 
dividual is  dependent  upon  his  knowledge  of  the  things 
about  him,  and  upon  the  understanding  that  he  has  of 
their  relations  to  each  other  and  to  himself.  This  knowl- 
edge and  apprehension  of  relations  can  only  be  acquired 
by  actual  personal  contact  and  experience  with  the  things 
and  forces  which  make  up  and  govern  the  universe.  It 
is  true,  the  concept  of  a  tree,  gained  from  the  study  of 
the  object  itself,  furnishes  a  starting  point  for  a  great  deal 


NATURE    STUDY. 


of  knowledge  about  trees  in  general,  but  that  knowledge 
is  weak  and  inaccurate  so  far  as  the  objects  described 
differ  from  that  upon  which  the  original  concept  is 
based.  The  avenues  through  which  the  elements  of  the 
concept  must  be  gained  are  the  senses,  and  therefore 
the  very  essence  of  science  work,  upon  whatever 
plan  conducted,  must  be  direct,  individual  observation. 
The  material  selected  should  be  of  such  character  as  will 
provide  the  mind  with  the  most  useful  concepts.  It  will 
be  a  matter  of  profound  surprise  to  any  one  who  will 
take  the  trouble  to  investigate,  to  find  how  vague  the 
ideas  of  very  commonplace  things  are  in  the  minds  of 
many  persons  who  are  to  be  classed  as  intelligent  and 
even  educated.  Critics  make  merry  over  patient 
endeavor  to  get  pupils  to  do  simple,  easy  things, 
which  they  say  are  self-evident  from  the  very  dawn  of 
intelligence.  Yet,  the  teacher  will  likely  make  a  great 
mistake  if  he  takes  very  many  of  even  the  simplest  con- 
ceptions for  granted.  It  is  a  proposition  needing  no 
demonstration  that  without  these  conceptions  the  reason- 
ing faculty  is  powerless. 

But  true  science  work  does  not  stop  with  mere  seeing, 
hearing,  or  feeling  ;  it  not  only  furnishes  a  mental  pic- 
ture as  a  basis  for  reasoning,  but  it-includes  an  interpre- 
tation of  what  has  been  received  through  the  senses.  A 
child  and  a  goat  may  see  the  same  thing,  with  the  ad- 
vantage of  vision  on  the  side  of  the  goat  ;  but  the  latter 
has  no  power  to  interpret  what  he  sees,  and  is,  therefore, 
essentially  non-scientific.  In  these  early  interpreta- 
tions, lie  the  beginnings  of  the  reasoning  power,  and  with 
its  development  comes  self-reliance,  independence  of 
thought,  and  a  general  strength  of  character  which 
marks  a  man  among  men.  If  a  pupil  be  permitted 


THE  MOTIVE.  3 

to  carefully  examine  an  object  or  a  set  of  conditions, 
and  then  be  required  to  interpret  what  he  sees,  he  is 
from  that  moment  ever  after  stronger  than  he  was 
before.  By  that  act,  no  matter  how  trivial,  he  begins 
the  great  work  of  self-emancipation  from  the  rule  of 
chance  in  so  far  as  his  interpretation  has  taught  him 
how  the  forces  about  him  may  be  resisted,  guided,  and 
controlled. 

A  great  work  is  to  be  done  by  inculcating  living  truth  ; 
but  one  equally  important  must  be  accomplished  in 
rooting  out  the  influence  ^of  inherited  errors.  We 
are  not  yet  free  from  the  dominion  of  some  super- 
stitions as  dark  as  any  that  ever  existed.  There  is  a 
pressing  need  that  the  pupils  be  taught  the  truth  about 
the  laws  of  nature  and  about  common  things  that,  at 
least,  they  may  not  hereafter  become  the  prey  of  the 
unscrupulous.  It  is  by  no  means  uncommon  to  find  an 
advertisement  of  goodly  proportions  in  daily  papers, 

setting    forth    that    Madame    ,    seventh    daughter 

of  the  seventh  son,  of  necessity  possessing  occult  power, 
will,  for  a  very  small  consideration,  reveal  much  that  is  of 
the  highest  importance  to  those  in  trouble,  or  otherwise 
in  need  of  such  information.  Such  advertisements  throw 
strong  side  lights  upon  the  present  condition  of  the 
popular  mind,  from  a  scientific  point  of  view.  Properly 
interpreted,  they  mean  that  there  are  enough  people 
about  us,  so  grossly  ignorant  of  natural  laws,  that  they 
are  the  willing  victims  of  a  base  fraud  to  the  extent  of 
supporting  it  in  idleness  at  a  handsome  income,  no  doubt, 
after  paying  all  expenses  for  advertisements  and  an 
establishment.  But  there  is  a  larger  class,  perhaps,  who 
will  only  plant  their  seeds  in  the  light  of  the  moon,  who 
never  begin  anything  on  Friday,  who  dislike  to  be  called 


4  NATURE   STUDY. 

number  thirteen,  and  for  whom  a  broken  looking-glass 
bodes  disaster. 

The  people  of  the  present  time  over  fifty  years  of  age, 
who  are  absolutely  free  from  such  superstition,  are  the 
exception.  And  still  further  interpreting,  in  the  r_.  -st 
narrow  manner,  Pope's  dictum,  "  The  proper  study  of 
mankind  is  man,"  pupils  are  actually  taught  to  despise 
a  great  many  creatures  and  things  which  probably  play 
as  important  a  part  in  the  economy  of  the  universe  as  do 
the  lords  of  creation.  In  these  times  of  indiscriminate 
pistol  practice,  nothing  should  be  done  which  would  tend 
to  lower  the  value  of  human  life  in  the  estimation  of  the 
pupils  ;  but,  in  view  of  the  ruthless  and  utterly  pur- 
poseless slaughter  of  the  harmless  members  of  the  so- 
called  brute  creation,  the  regard  for  human  life  seems 
almost  exaggerated.  The  average  boy  may  be  tracked 
through  the  woods  by  the  blood  of  the  innocent  creatures 
he  destroys — a  wanton  destruction,  based  upon  utter 
ignorance  of  the  function  of  these  creatures  and  upon 
groundless  fears.  From  earliest  childhood  the  notion  is 
implanted  that  in  most  living  things  about  him,  of  the 
brute  creation,  there  is  a  hidden  danger  to  his  life  or 
comfort.  Then  through  the  maxim  that  self-preserva- 
tion is  the  first  law  of  nature,  he  logically  reaches  his 
watchword,  "kill."  But  if  the  truth  were  known,  it  is 
hardly  an  exaggeration  to  say  that  not  one  person  in  a 
thousand  meets  one  thing  in  a  thousand  in  the  whole 
course  of  a  year,  which  would  do  him  the  least  harm. 
On  the  other  hand,  how  many  that  are  thoughtlessly 
destroyed  do  incalculable  good  ?  The  notion,  too, 
that  fear  of  certain  things  and  horror  of  others  is  in- 
stinctive and  natural,  is  totally  false,  as  any  one  may 
prove  for  himself  by  observing  a  little  child.  He  is 


THE  MOTIVE.  5 

as  much  interested  in  a  snake  as  in  a  kitten,  and  fondles 
one  as  freely  as  the  other. 

Ignorance  of  natural  law  is  no  less  marked  in  its 
effects  upon  us  than  ignorance  of  living  objects.  Too 
many  people  still  see  in  the  lowering  thunder  cloud 
little  else  than  the  chariot  of  a  great  avenger  ;  who  re- 
gard the  lightning's  stroke,  the  flood,  and  the  fire  chiefly 
as  expressions  of  vindictive  power.  Speed  the  happy 
day  when  the  general  diffusion  of  scientific  knowledge 
shall  remove  from  the  mind  of  man  "the  last  vestige  of 
that  feeling  that  he  is  being  hunted  off  the  face  of  the 
earth,  the  victim  of  a  mighty  wrath.  Then,  for  the  first 
time  in  the  evolution  of  the  race,  will  he  be  in  the  perfect 
attitude  of  a  true  student  of  nature. 

While  the  motives  for  instruction  in  science  here  given 
may  seem  valid  and  of  sufficient  importance  to  warrant  a 
place  for  it  in  the  common  schools,  there  is  yet  one 
thing  lacking.  The  "  Enacting  Clause,"  to  give  positive 
character  and  vitality  to  the  work,  must  be  added.  "  For 
what  good"  must  have  an  answer  in  a  motive,  which 
makes  science  instruction  something  more  than  a  merely 
pleasant  or  fashionable  pastime  for  both  pupil  and 
teacher.  The  true  incentive  will  make  scientific 
knowledge  a  necessity,  and  will  do  more  than  rouse 
simply  a  kind  of  adventitious  interest  in  the  works  of 
nature.  If  it  go  no  farther  than  this,  then  the  teacher 
will  be  utterly  unable  to  reach  the  pupil  who  says  by 
word  and  action  that  he  cares  nothing  for  nature. 
The  final  motive  for  the  study  of  science  is  to  bring 
the  pupil  by  degrees  to  a  strong  personal  realization  that 
he  is  the  focus  of  innumerable  forces  about  him  which  so 
bear  upon  him,  and  so  limit  his  life  and  comfort,  as  to 
render  the  knowledge  of  how  they  may  be  resisted, 


6  NATURE   STUDY. 

guided,  and  controlled,  an  absolute  necessity.  Life,  ulti- 
mately his  own  life,  is  the  great  center  of  all  his  interest 
in  the  world  ;  and  this  motive  will  co-ordinate  his  interest 
in  nature  exactly  with  his  interest  in  his  own  existence. 
This  will  give  him  life  in  the  broadest  and  best  sense, 
which  is  the  ultimate  aim  of  all  education.  Thus  science 
instruction  takes  its  place  in  the  common  schools  with  a 
motive  at  once  pure  and  beneficent,  and  with  an  irre- 
sistible appeal  to  all  to  become  life-long  students. 
Many  a  boy  who  little  cares  whether,  by  the  laws  of 
gravitation,  a  stone  is  pulled  downward  or  pushed  up- 
ward, will  become  interested  intensely,  when  he  realizes 
that  he  is  under  its  constant  operation  until  it  finally 
pulls  him  downward  into  his  grave.  The  mechanics  of 
the  lever  is  only  so  much  " stuff  and  nonsense"  to  him, 
until  he  finds  that  this  knowledge  will  render  possible  an 
economy  of  his  energy,  and  thereby  immensely  prolong 
his  mortal  existence.  In  short,  all  phenomena  of  earth 
and  air  are  pregnant  with  the  deepest  interest  when  he 
finds  himself  threatened  through  his  ignorance  and  his 
inability  to  interpret  them.  When  we  for  a  moment  con- 
sider how  important  this  knowledge  is,  and  how  little  of 
what  we  possess  was  obtained  in  the  schools,  need  we  be 
amazed  to  find  that  the  average  duration  of  human  life 
is  but  one-third  of  its  possible  length  ? 

No  one  has  more  clearly  shown  this  point  than  Prof. 
Huxley,  who  says  :  "  Suppose  it  were  perfectly  certain 
that  the  life  and  fortune  of  every  one  of  us  would,  one 
day  or  other,  depend  upon  his  winning  or  losing  a 
game  of  chess.  Don't  you  think  that  we  should  all  con- 
sider it  to  be  a  primary  duty  to  learn  at  least  the  names 
and  moves  of  the  pieces  ;  to  have  a  notion  of  a  gambit, 
and  a  keen  eye  for  all  the  means  of  giving  and  getting 


THE  MOTIVE.  7 

out  of  check?  Do  you  not  think  that  we  should  look 
with  disapprobation,  amounting  to  scorn,  upon  the  father 
who  allowed  his  son,  or  the  state  which  allowed  its  mem- 
bers, to  grow  up  without  knowing  a  pawn  from  a  knight  ? 
Yet  it  is  a  very  plain  and  elementary  truth  that  the  life, 
fortune,  and  the  happiness  of  every  one  of  us,  and  more 
or  less  of  those  who  are  connected  with  us,  do  depend 
upon  our  knowing  something  of  the  rules  of  a  game  in- 
finitely more  difficult  and  complicated  than  chess.  It  is 
a  game  which  has  been  played  for  untold  ages,  every 
man  and  every  woman  of  us  being  one  of  the  two  players 
in  a  game  of  his  or  her  own.  The  chess-board  is  the 
world,  the  pieces  are  the  phenomena  of  the  universe,  the 
rules  of  the  game  are  what  we  call  the  laws  of  nature. 
The  player  on  the  other  side  is  hidden  from  us.  We 
know  that  his  play  is  always  fair,  just,  and  patient.  But 
also  we  know  to  our  cost  that  he  never  overlooks  a  mis- 
take or  makes  the  smallest  allowance  for  ignorance. 
To  the  man  who  plays  well,  the  highest  stakes  are  paid 
with  that  sort  of  overflowing  generosity  with  which  the 
strong  shows  delight  in  strength,  and  one  who  plays  ill 
is  checkmated,  without  hastef  but  without  remorse.  My 
metaphor  will  remind  some  of  you  of  the  famous  picture 
in  which  Retzsch  has  depicted  Satan  playing  at  chess 
with  a  man  for  his  soul.  Substitute  for  the  mocking 
fiend  in  that  picture  a  calm,  strong  angel,  who  is  playing 
for  love,  as  we  say,  and  would  rather  lose  than  win,  and 
I  should  accept  it  as  an  image  of  human  life." 


o  NATURE   STUDY. 

CHAPTER   II. 

PRINCIPLES. 

IT  is  obvious  that  the  methods  of  instruction  adopted 
by  the  teacher  in  any  subject  should  be  those  which  suit 
themselves  to  the  natural  conditions  of  the  pupil.  The 
proper  clew  which  will  enable  the  teacher  to  determine 
upon  the  principles  which  must  guide  him  in  his  methods 
of  instruction  in  elementary  science,  must  come,  there- 
fore, from  a  close  study  of  the  child.  The  normal  child 
himself  will  tell  by  his  actions  what  things  appeal  earliest 
and  most  strongly  to  him,  and  will  thus  indicate  to  the 
teacher  the  lines  along  which  it  is  best  to  guide  him. 
The  time  has  come  for  teachers  when  "a  little  child 
shall  lead  them." 

If  it  is  perfectly  safe  to  take  the  spontaneous  develop- 
ment of  the  child's  mind  under  the  influence  of  his 
natural  environment  as  a  guide  in  instructing  him,  it  is 
necessary  for  the  teacher  to  carefully  study  the  child's 
methods  and  to  critically  scan  both  the  kind  and  the 
character  of  the  knowledge  he  acquires.  With  this  in 
mind,  turn  him  loose  for  a  time  upon  the  world  and  give 
him  rein.  He  will  return  by  and  by,  in  his  realm  a  dis- 
coverer and  a  conquerer.  He  will  tell  of  the  flowers 
that  he  finds  in  his  pathway  ;  of  the  trees,  and  of  the 
birds  which  sing  in  their  branches.  He  tells  of  the 
shining  pebble  and  sparkling  sand  beneath  his  feet,  and 
of  the  great  clouds  rolling  through  the  heavens  overhead. 
He  has  found  the  tiny  insect  in  its  hidden  home,  and  the 
remotest  star  whose  radiance  strikes  his  eye.  He  has 
watched  the  wonderful  journey  of  the  sun  from  the 
earliest  morning  ray,  till  the  last  golden  shaft  at  night, 


PRINCIPLES.  9 

and  feels  anew  his  delight  at  the  appearance  of  the  silver 
moon.  He  has  been  startled  by  the  lightning's  flash  and 
awed  into  silence  by  the  roar  of  thunder.  He  has  seen 
the  stream  winding  its  way  to  the  river,  now  peaceful, 
and  again  as  a  roaring  torrent  tearing  its  banks  and 
building  bars,  and  he  has  seen  the  fog  lifting  itself  from 
the  valleys.  He  has  been  fanned  by  the  soft  winds  of 
summer,  and  chilled  by  the  blasts  of  winter.  He  has 
tried  to  bathe  himself  in  the  glories  of  the  rainbow  and 
he  has  coveted  the  diamonds  of  the  dew.  He  has  been 
drenched  by  the  pelting  rainstorm  and  he  has  rolled  him- 
self in  the  blanket  of  snow.  He  has  witnessed  that 
great  resurrection  in  spring-time,  and  has  seen  the  living 
world  grow,  mature,  and  die,  almost  as  he  rouses  him- 
self from  slumber  in  the  morning,  and  sinks  to  rest  again 
at  night.  He  has  tested  his  own  strength  and  feels  some- 
thing of  his  own  possibilities  and  limitations.  In  short, 
the  great  universe  of  God  has  been  spread  before  him 
and  he  has  scanned  the  whole  as  an  open  page. 

This  observation  illustrates  two  important  points — the 
only  ones,  it  may  be  said,  necessary  to  consider,  in  for- 
mulating a  course  of  study.  First,  it  gives  a  true  idea  of 
the  scope  of  a  child's  observations,  and  second  it  indi- 
cates the  character  of  the  knowledge  he  can  acquire.  It 
is  amazing  to  find  what  a  field  of  observation  is  open 
for  a  child  but  two  years  of  age.  Every  nook  and 
corner  of  the  house  is  explored  and  becomes  part  of  the 
known.  He  ranges  through  the  door-yard,  garden, 
and  farm,  and  learns  the  names  of  fruits,  animals,  and 
places.  He  takes  up  everything  with  such  avidity  and  so 
rapidly  that  it  would  seem,  if  he  could  be  kept  growing 
at  the  same  rate  until  he  has  lived  through  the  years  al- 
lotted to  the  common  school  course  only,  he  would  be  a 


10  NATURE   STUDY, 

renowned  scientist.  That  this  marvelous  interest  does 
flag,  however,  is  painfully  evident,  and  the  question  that 
pressess  itself  home  is,  Who  is  reponsible  for  it  ?  Who, 
indeed,  can  be  but  the  teacher  ?  The  child  comes  to 
him  with  an  expanding  soul,  even  as  all  have  felt 
their  souls  expanding  once,  under  the  genial  influ- 
ences of  nature,  and  the  school  proceeds  to  deliber- 
ately squeeze  the  life  out  of  him  with  the  same  modes 
of  instruction  which  squeezed  the  life  out  of  the  gener- 
ations before  him.  He  comes  to  the  teacher  with  his 
eyes  filled  with  a  thousand  pictures,  but  they  are  ignored, 
and  he  is  robbod  of  them  one  by  one  until  at  last  the 
beauty  of  this  world  fades  from  his  sight  and  it  is  changed 
to  a  vale  of  tears.  In  the  beginning  of  science  instruc- 
tion and  to  the  end,  the  fact  must  be  recognized  that  the 
child  stands  at  the  center  of  the  universe,  and  from  first 
to  last  is  touched  by  everything  in  it.  A  complete  and 
symmetrical  course  of  instruction  must  proceed  outward 
from  this  center  though  the  phenomena  that  surround 
it  to  the  laws  that  lie  beyond  them.  By  such  a  course 
only  can  the  teacher  hope  to  impress  upon  the  pupil  his 
true  relations  to  the  things  and  forces  about  him. 

It  remains  to  make  more  specific  inquiry  as  to  how  the 
teacher  shall  proceed  in  order  to  attain  this  end.  Turn 
again  to  the  child  in  direct  contact  with  nature,  and 
look  into  the  character  of  the  knowledge  he  acquires. 
If  he  tells  about  a  flower,  it  will  probably  be  something 
of  its  color  ;  if  about  a  bird,  its  song  or  its  plumage  ;  if 
about  a  pebble,  its  smoothness  or  roundness,  and  so  on- 
The  character  is  unmistakable.  It  is  all  breadth  and  no 
depth. 

This  interpretation  of  the  action  of  the  child-mind 
meets  with  opposition  because  it  seems  to  encourage  su- 


PRINCIPLES.  1 1 

perficiality.  But  the  clew  thus  obtained  from  the  child 
himself  gives  unmistakable  evidence  as  to  the  course  the 
teacher  should  pursue.  It  is  a  radical  error  to  attempt 
to  make  specialists  of  the  pupils  from  the  beginning. 
Undue  prominence  given  to  any  particular  branch  of 
science  in  the  common  schools  will  lead  to  one-sided 
development,  and  in  the  end  to  superficial  work.  Early 
specialization  leads  inevitably  to  a  certain  linear  arrange- 
ment of  the  different  branches  of  science  which  is 
radically  wrong  in  its  conception  and  misleading  and 
confusing  in  its  effects. 

The  arrangement  of  the  subjects  so  that  one  shall,  in  turn, 
succeed  another  in  regular  order  (this  not  being  the  same 
in  any  two  schools),  is  a  device  which  has  done  the  most 
to  obscure  the  relations  of  the  so-called  branches  of 
science  to  each  other  and  to  the  child.  However  neces- 
sary such  an  arrangement  may  be  for  an  advanced 
course,  in  elementary  work  there  is  not  the  slightest 
foundation  for  it,  either  in  nature  as  it  presents  itself  for 
study,  or  in  the  conditions  under  which  the  child's  mind 
develops.  Nor  is  it  so  important  as  many  teachers  sup- 
pose to  use  the  material  afforded  by  any  particular  sub- 
ject in  a  fixed  order,  in  zoology,  for  example,  it  matters 
not  the  least  whether  the  child  begins  with  a  vertebrate 
or  an  invertebrate,  provided,  in  that  particular  thing 
there  is  something  which  he  wishes  to  study.  In  botany, 
it  matters  not  whether  it  be  a  fungus  or  a  flower  that 
opens  up  this  great  kingdom  of  life  to  him.  The  mistake 
made  on  this  point  by  teachers  is  a  fundamental  one,  and 
it  lies  in  supposing  that  those  objects  which  are  physically 
near  to  the  child  are  the  only  ones  which  have  a  psychic 
nearness.  A  bright  butterfly,  or  even  an  oyster,  is  much 
nearer,  psychically,  to  the  child  than  a  horse. 


12  NATURE   STUDY. 

In  disposing  of  this  difficult  question  of  arranging  a 
course  of  study  and  selecting  suitable  material,  the 
teacher  must  take  his  cue  from  nature  and  from  his  own 
immediate  surroundings.  Science  teaching  indoors  will 
be  vastly  enhanced  if  it  be  supplemented  and  reinforced 
by  nature  outside.  The  work  should  therefore  be 
planned  to  suit  the  changing  and  recurring  seasons. 
This  is  best  because  it  is  most  natural,  for  the  child  is 
placed  in  contact  with  nature  under  normal  conditions, 
and  it  is  much  more  easy  for  the  teacher  and  pupils  to 
obtain  appropriate  material.  It  is  true,  flowers  may  be 
studied  in  winter  time  ;  but  to  the  child  they  are  freaks, 
and  such  a  study  is  a  distortion  of  the  subject  to  his 
mind,  and  it  gives  the  teacher  endless  trouble.  A  study 
of  the  plant,  with  its  buds  housed  in  their  winter  quar- 
ters or  with  its  seeds  buried  in  frozen  soil,  is  an  appro- 
priate subject  for  the  season,  and  the  supply  of  material 
is  natural  and  abundant. 

The  most  serious  obstacle  in  the  way  of  science  work 
is  the  teacher's  own  lack  of  faith  in  his  ability  to  do  any- 
thing useful  or  creditable.  He  should  without  hesitation 
begin  with  the  simple  things  around  him,  and  grow  with 
the  pupils.  The  crude  and  scanty  appliances  at  hand, 
well  used,  will  open  the  way  for  better  ones  which  will 
surely  come,  for,  in  the  end,  the  schools  are  not  to  suffer 
from  the  want  of  any  really  good  thing. 


EXPKESSfOtf.  13 

CHAPTER  III. 

EXPRESSION. 

THE  value  of  science  work  to  the  pupil  is  very  greatly 
enhanced  by  a  complete  and  clear  but  concise  expression. 
Success  in  teaching  the  subject  depends  so  largely  upon 
the  teacher's  judgment  in  using  the  appropriate  modes  of 
expression  at  the  proper  stage  of  each  particular  kind  of 
work,  that  it  becomes  necessary  to  give  the  subject  care- 
ful attention.  Teachers  usually  lay  much  stress  upon 
oral  and  written  language  ;  but  valuable  as  they  may  be, 
they  are  inadequate  to  the  demands  which  a  study  of 
science  makes  upon  the  pupil  for  thought  expression. 

In  order  that  the  subject  of  expression  may  be  under- 
stood, it  is  necessary  to  consider  it  in  its  relation  to  the 
means  by  which  knowledge  is  gained.  The  various 
modes  of  expression  have  a  natural  basis  in  the  different 
modes  of  study.  By  a  mode  of  study  is  meant  the  means 
and  the  process  by  which  the  mind  receives  data  from 
the  world  without.  These  modes  may  be  included  under 
three  heads,  as  follows  :  First,  the  study  of  the  object ; 
second,  the  study  of  the  object  by  some  means  which 
partially  symbolize  it,  and  third,  the  study  by  means, 
of  symbols  only. 

The  first  mode  mentioned,  ordinarily  termed  direct 
obgervation,  may  call  into  play  any  or  all  the  senses, 
touch,  sight,  hearing,  taste,  smell,  and  the  muscular  sense. 
On  the  other  hand,  the  real  object  under  observation 
presents  all  the  attributes  which  can  be  cognized  by  the 
mind.  As  a  result,  having  received  one  or  more  elemen- 
tary ideas  through  one  or  more  of  the  senses,  the  mind 
forms  for  itself  a  mental  product  which  has  the  closest 


14  NATURE   STUDY. 

possible  correspondence  to  the  real  object  without. 
This  is  the  concept  of  the  object. 

The  second  mode  of  study  makes  use  of  pictures  or 
models,  and  to  a  limited  extent  of  onomatopoetic  words, 
which  cannot  present  directly  all  the  attributes  of  the 
real  object,  but  may  partially  or  wholly  symbolize  them. 
Fewer  of  the  senses  may  therefore  be  engaged  in  this, 
and  an  imperfect  concept  is  the  necessary  result. 

The  third  mode  of  study  is  by  means  of  hearing  lan- 
guage and  reading,  and  consequently  has  to  do  with  pure 
symbols  only.  With  the  exception  of  an  occasional  ono- 
matopoetic word,  before  mentioned,  whatever  may  have 
been  the  origin  of  the  symbols,  they  cannot  now  be 
properly  considered  the  attributes  of  any  object.  Their 
function  is  simply  to  "arouse  in  the  mind  certain  activities 
which  form  the  concept  from  data  already  there. 

In  its  broad  sense,  the  function  of  expression  is  to 
produce  an  external  thing  which  corresponds  to  the  inter- 
nal concept.  The  motive  for  expression  is,  subjective, 
to  intensify  the  thought  of  the  one  expressing  it,  and, 
objective,  to  convey  that  though c  to  others.  Ethically 
considered,  expression  may  be  either  selfish  or  unselfish, 
but  there  is  naturally  no  conflict  between  the  two  ends. 
The  more  clearly  defined  and  intense  the  thought  be- 
comes to  the  individual,  the  better  can  he  convey  it  to 
others,  and  there  is  a  naturally~increasing  desire  to  do  so. 

The  modes  of  expression  have  a  natural  correspon- 
dence to  the  modes  of  study  above  outlined.  They  may 
be  included  under  the  heads  of  gesture  (including  facial 
expression,  and  attitude),  music  without  words  (including 
the  different  tones  of  voice  used  in  oral  language,  and 
all  moans  and  cries),  making,  modeling,  painting,  draw- 
ing, oral  language  and  written  language.  Each  mode  of 


EXPRESSION.  15 

expression  is  peculiar  in  this,  that  it  has  a  special  function 
of  its  own  which  cannot  be  perfectly  performed  by  any 
other  one  or  more  modes,  though  of  course  they  do 
supplement  each  other  in  almost  every  expression  of 
thought. 

Closely  associated  with  oral  language,  and  from  which 
it  may  have  arisen,  are  the  two  modes  above  classed 
under  gesture  and  music.  The  peculiar  function  of 
these  most  subtle  forms,  the  one  appealing  to  the  eye 
and  the  other  to  the  ear,  is  to  convey  directly  from  mind 
to  mind  the  idea  of  emotion.  No  other  mode  has  the 
adequacy  of  either  of  these  for  this  purpose.  They  each 
convey  an  idea  of  something  which  is  absolutely  beyond 
the  domain  of  material  representation.  They  place  man 
in  immediate  touch  with  his  fellow-man,  and  form  the 
universal  soul-bond  of  humanity — nay,  of  all  animate 
creation,  for  by  them  we  even  understand  the  brutes, 
and  they  us  and  each  other.  Originally  of  objective 
value  chiefly,  now  all  training  in  attitude,  gesture, 
and  modulation  of  voice,  takes  advantage  of  the  power 
which  these  have  to  intensify  the  thought  in  the  one 
giving  it  expression.  The  data  for  the  thoughts  which 
find  expression  by  these  means  may  be  gathered  through 
any  or  all  of  the  senses. 

The  difficulties  encountered  by  the  teacher  in  dealing 
with  these  two  modes  are  different  from  those  which  arise 
in  teaching  any  of  the  others.  Whereas  the  others  are  more 
or  less  arbitrary,  these  are  perfectly  natural,  and  they  are 
the  result,  not  of  teaching,  but  of  heredity.  The  difficulty 
lies  in  co-ordinating  the  more  arbitrary  forms  with  them. 
To  make  the  word  exactly  correspond  to  the  look,  gesture, 
or  tone  is  the  thing  to  be  sought.  The  naturalness  of 
these  modes  is,  unfortunately,  very  early  lost,  in  most 


1 NATURE   STUDY. 

cases  through  a  soul-consuming  self-consciousness,  and  it 
is  regained  with  the  greatest  difficulty.  Upon  its  proper 
co-ordination  with  these  modes,  the  general  intelligibility 
of  oral  expression  depends,  and  by  them  the  teacher  has 
an  almost  exact  measure  of  the  intensity  of  the  pupil's 
thought  and  of  his  interest  and  comprehension  of  the 
subject  in  hand. 

Making  is  the  most  definite  and  complete  mode  of 
expression  where  material  representation  is  possible. 
This  is  because  the  maker  becomes  acquainted  not 
only  with  the  object  in  all  of  its  parts  and  as  a  whole, 
but  also  with  the  nature  of  the  substances  with  which  he 
works.  As  it  is  only  by  a  study'  of  the  real  object 
that  all  of  its  attributes  appeal  to  the  mind,  so  it  is 
only  by  making,  that  the  exact  external  correspondence 
to  the  concept  of  these  can  be  reproduced.  It  is  the 
peculiar  function  of  making  to  give  this  external  corre- 
spondence material  form.  It  is  the  simplest  and  lowest 
mode  because  there  are  no  mental  pictures  involved  that 
do  not  have  a  concrete  basis  in  the  material  before  the 
maker.  It  is  a  universal  mode  because  the  idea,  that  of  a 
certain  box,  for  example,  will  be  expressed  by  all  in  the 
same  way.  This  allies  it  closely  with  the  two  preceding 
forms. 

The  data  for  this  mode  of  expression  are  gathered 
through  all  of  the  senses,  and  it  therefore  follows  that  in 
the  outward  material  representation  of  the  idea,  each 
sense  may  act  as  a  corrective  upon  all  of  the  others  and 
thus  making  becomes  one  of  the  easiest  modes.  Great 
difficulties  arise,  however,  due  to  the  peculiar  and  various 
properties  of  the  materials  employed,  such  as  wood,  stone, 
iron,  and  glass.  This  is  further  enhanced  by  the  inability 
to  properly  estimate  the  value  of  solid  angles  and  lines  and 


EXPRESSION.  17 

by  the  lack  of  skill  necessary  to  form  flat  and  curved 
surfaces. 

Science  work  offers  great  opportunities  for  this  mode 
of  expression.  Throughout  the  whole  of  physics  and 
chemistry  there  are  almost  numberless  pieces  of  appa- 
ratus and  devices  which  should  be  made  by  the  pupil. 
The  difficulties  peculiar  to  this  mode  are  more  than  bal- 
anced by  the  intense  interest  which  the  pupil  always  has 
in  making  something.  It  brings  him  to  the  joy  of  a  new 
creation  in  which  he  plays  the  role  of  creator,  and,  in  the 
cultivation  of  self-reliance,  this  can  hardly  be  overesti- 
mated. And  when  still  further,  as  in  the  Sloyd,  it  is  the 
thought,  "This  is  for  some  one  I  love — for  father  or 
mother,"  that  drives  the  plane  or  handsaw,  it  makes  it,  in 
its  reflex  upon  character,  second  to  no  other  moral  influ- 
ence. 

Modeling,  in  itself,  has  to  do  entirely  with  form,  both 
external  and  internal,"  and  so  far,  it  is  identical  with 
making.  As  a  mode  of  expression,  though,  it  is  differ- 
entiated from  making  in  regard  to  size.  An  object  may 
be  modeled  many  times  as  large  or  small  as  that  of  which 
it  is  intended  to  give  the  idea.  The  data  for  the  model 
are  gathered  through  the  senses  of  sight  and  touch,  and 
while,  therefore,  the  judgment  lacks  some  of  the  safe- 
guards thrown  around  it  in  making,  this  is  offset  by  the 
fact  that  there  is  less  of  the  complete  idea  to  be  expressed 
by  it.  The  difficulty  to  be  overcome  in  modeling,  as 
in  making,  is  in  the  estimation  of  solid  angles  and  in 
the  formation  of  curves  and  plane  surfaces.  The  mate- 
rial used  may  be  of  such  character  as  to  reduce  the  diffi- 
culty of  its  manipulation  to  the  minimum. 

The  use  of  this  mode  in  science  work  is  varied.  In 
zoology,  clay  modeling  may  be  used  with  great  advantage 


1 8  NATURE   STUDY. 

in  the  study  of  the  larger  animals  and  in  the  study  of  the 
skeleton.  In  botany,  early  study  of  roots,  the  various 
forms  of  underground  stems  and  fruits  will  necessitate 
its  use.  In  geography,  geology,  and  mineralogy  either 
sand  or  clay  may  be  used  to  show  the  relief  of  any  given 
area  covered  by  an  excursion  or  a  field-lesson,  and  the 
latter  is  specially  fitted  for  showing  rock  strata,  dip,  and 
forms  of  crystals. 

Painting  as  a  mode  of  expression  is  unique.  Its  peculiar 
function  is  to  give  the  idea  of  color — something  which  can- 
not be  even  approximated  by  any  other  mode.  It  stands  in 
contrast  with  both  making  and  modeling,  because  it  is 
primarily  independent  of  volume,  size,  and  substance.  It 
can,  it  is  true,  be  made  to  suggest  solidity  of  form  after 
the  idea  has  been  gained  by  other  means. 

The  data  for  painting  are  gathered  through  the  sense 
of  sight  alone.  The  chief  difficulty  which  besets  the 
judgment  is  due  to  the  fact  that  there  is  no  corrective  sense; 
if  the  eye  fails  to  give  the  proper  datum  there  is  no  other 
means  by  which  the  mistake  may  be  discovered. 

In  a  large  part  of  elementary  science  work  the  value 
of  painting  can  hardly  be  overestimated.  Primary  pu- 
pils can  tell  far  more  with  their  brushes  and  colors,  and 
can  tell  it  much  better  than  they  can  with  either  tongue, 
pen,  or  pencil.  It  will  greatly  enhance  interest  in  the 
study  of  birds,  insects,  fruits,  flowers,  leaves,  and  min- 
erals. 

In  drawing,  the  chief  thing  to  be  expressed  is  outline, 
not  only  of  the  whole,  but,  also  that  of  the  parts  of  an 
object.  This  mode  of  expression,  closely  related  to 
painting  on  one  side  and  to  making  and  modeling  on  the 
other,  is  independent  of  solidity  of  form  and  size.  It  is 
allied  to  modeling  and  more  remotely  to  making  because 


EXPRESSION.  19 

it  deals  with  form,  but  only  so  far  as  it  can  be  expressed 
in  outline  without  giving  the  idea  primarily  of  volume. 
The  chief  difficulty  in  cultivating  this  form  of  expression 
with  beginners  lies  in  a  lack  of  muscular  control  which 
is  necessary  in  drawing  straight  and  curved  lines,  and  in 
the  errors  of  judgment  in  the  measurement  of  angles  and 
estimation  of  distances.  The  judgment  is,  in  this  form 
of  expression,  dependent  upon  sight  alone,  and  in  this 
respect  it  is  allied  to  painting. 

In  science,  drawing  may  be  employed  with  great  ad- 
vantage in  all  subjects.  Its  earliest  application  is  found 
in  the  representation  of  apparatus  used  in  physics  and 
chemistry,  and  all  material  where  sharpness  of  outline 
and  detail  of  structure  are  required. 

Between  written  language  and  the  forms  of  expression 
already  considered,  there  is  a  wide  difference.  It  is 
wholly  an  arbitrary  means  of  expressing  thought,  and 
can  intensify  it  subjectively  only  in  this  way  :  by  means 
of  the  device  of  which  this  mode  of  expression  makes  use 
— that  is  the  written  sentence — a  relation  is  expressed 
which  by  the  aid  of  this  visible  sign,  is  held  more  steadily 
before  the  mind  as  an  object  of  study.  In  function,  it  is 
distinguished  from  the  preceding  modes  by  the  fact  that 
certain  relations  may  be  directly  expressed  by  it  which  lie 
wholly  beyond  their  domain.  "  Man  should  help  his 
fellow-man,"  expresses  an  obligation  ;  by  the  written 
sentence,  this  idea  is  conveyed  to  others — something 
which  could  not  be  accomplished  by  any  other  single 
mode. 

The  judgment  expressed  by  the  written  sentence  rests 
upon  data  that  may  be  gathered  through  every  avenue 
of  sense.  The  chief  difficulty  is  in  the  lack  of  muscular 
control  which  is  necessary  to  guide  the  pen,  and  in  mak- 


20  NATURE    STUDY. 

ing  the  arbitrary  association  of  certain  letters  with  defin- 
ite sounds  which  the  former  represents. 

In  science  work,  written  language  is  of  universal  appli- 
cation as  a  mode  of  expression.  Too  often,  however, 
its  use  is  demanded  when  some  other  mode  would  be 
more  appropriate. 

Closely  allied  to  written  expression  is  that  by  oral 
language.  It  is  related  to  written  language,  and  differs 
from  all  the  other  modes  because  ideas  can  be  expressed 
by  it  which  are  beyond  the  reach  of  material  representa- 
tion by  any  other  single  form.  Its  peculiarity  is  found  in 
the  tone  of  voice  which,  independently  of  the  words  ut- 
tered, intensifies  or  diminishes  the  strength  and  clearness 
of  expression.  In  developing  this  form,  the  chief  obstacle 
is  encountered  in  the  difficulty  which  the  child  finds  in 
associating  his  thoughts  and  feelings  with  the  jingle  of 
sounds  which  represents  them  in  the  spoken  sentence, 
and  in  the  training  of  the  organs  concerned  in  articulate 
speech. 

All  of  the  senses  may  be  concerned  in  completing  the 
thought  which  finds  expression  in  oral  language.  Prac- 
tice with  this  form  of  expression  is  frequently  pushed 
too  far.  Teachers  are  naturally  ambitious  to  hear 
their  pupils  talk,  and  feel  disappointed  when  they  fail 
to  so  express  themselves.  Yet  with  children,  that 
it  is  wholly  inadequate,  sometimes,  for  the  full 
expression  of  the  thought,  is  a  fact  which  should  be 
recognized. 

While  expression  may  admit  of  the  foregoing  analysis, 
and  it  would  seem  that  each  mode  has  its  own  peculiar 
function,  it  will  be  observed  that  usually  two  or  more 
may  be  combined  in  the  expression  of  any  thought,  the 


EXPRESSION,  21 

fullness  and  clearness  of  which  are  greatly  enhanced 
thereby. 

It  remains  now  to  consider  the  natural  order  of  their 
development.  The  different  modes  are  not  developed 
entirely  seriatim,  but  something  of  the  serial  order  is  en- 
forced, in  practice,  by  certain  difficulties  before  mentioned 
in  connection  with  each.  Expression  is  primarily  de- 
pendent upon  external  stimuli,  and  it  follows  that  the 
mode  will  be  determined  somewhat  by  the  character  of 
the  stimulus  of  which  the  organism  is  susceptible,  and 
for  a  like  reason,  the  order  of  development  will  also  be 
somewhat  fixed. 

The  earliest  kind  of  stimuli  which  the  child  receives 
are  those  producing  bodily  pleasure  or  pain,  and  the  ex- 
pression corresponds.  The  smile  of  the  young  babe  in 
its  cradle  is  the  earliest  expression  of  that  light  which 
through  its  new-born  soul  is  destined,  it  may  be,  to  make 
luminous  the  dark  places  of  earth.  The  frown  flitting 
like  a  shadow  across  its  smooth  brow  is  the  earliest 
prophecy  of  a  spirit  which  is  born,  perhaps,  to  crush  a 
tyrant  and  emancipate  a  people.  This  mode,  coming  to 
the  child  by  heredity  alone,  has  no  conscious  relation 
at  this  time  to  the  thought  or  feeling  beneath  it. 

The  next  stimuli  are  received  through  the  sense  of 
sight,  derived  from  the  mere  presence  of  an  object 
and  through  the  sense  of  touch,  from  its  smoothness, 
roughness,  hardness,  or  softness  and  so  on.  The  appro- 
priate form  of  expression  is  by  oral  sounds  leading 
to  articulate  speech.  After  the  mere  presence  of  the 
object  is  made  known  the  next  stimulus  comes  from 
its  most  striking  peculiarity.  This  is  most  frequently 
received  through  the  sense  of  sight,  and  comes  usually 


22  NATURE   STUDY. 

from  the  color  of  the  object.  The  natural  and  appro- 
priate form  of  expression  is  by  use  of  brush  and  paint  in 
color  work.  The  pupil  constantly  compares  the  color  he 
uses  with  that  of  the  object,  and  thus  supplies  the  only 
corrective  to  his  judgment  possible  in  this  case.  Associ- 
ated closely  with  the  idea  of  color  is  that  of  form.  This 
demand  for  an  additional  mode  of  expression  is  met  by 
exercises  in  modeling.  This  order,  however,  should  often 
be  reversed,  since  peculiarity  of  form  is  sometimes  more 
conspicuous  than  brilliancy  of  color. 

Developing  considerably  later  than  the  ideas  of  color 
and  form  is  the  idea  of  the  outline  of  an  object.  The 
natural  expression  for  this  is  by  drawing.  Observation 
confirms  the  fact  that  drawing  with  the*  pencil  should  not 
begin  much  below  the  fourth  grade.  Previous  to  that  it 
may  be  practiced  on  the  black-board  in  much  broader 
outlines  and  with  less  details  than  that  required  by  the 
pencil.  This  is  not  only  because  detail  of  figure  does  not 
appear  early  to  the  pupil,  but  because  his  muscles  are  not 
yet  sufficiently  under  control.  The  arm  moves  the  hand 
chiefly  from  the  shoulder  ;  individual  muscles  that  move 
the  hand  and  fingers,  absolutely  necessary  to  fineness  of 
detail,  are  not  yet  separated  one  from  another  in  their 
functions.  This  difficulty  is  rapidly  and  completely 
overcome  by  giving  opportunities  for  blackboard  draw- 
ing when  the  full  arm  may  at  first  be  used  in  drawing 
large-sized  figures. 

Making  as  a  mode  of  expression  may  be  commenced 
very  early,  but  the  difficulties,  arising  from  a  lack  of 
knowledge  respecting  the  nature  of  the  materials,  some- 
what limit  its  range.  Its  use  is  further  diminished  by  the 
fact  that  many  things  studied  cannot  be  made.  This  is 
offset  by  the  intensely  practical  character  of  the  work- 


EXPRESSION.  23 

There  may  be  those  who  do  not  wish  to  paint,  who  can- 
not draw,  who  fear  to  speak,  or  are  too  lazy  to  write,  but 
a  pupil  is  rarely  to  be  found  who  will  not  be  interested 
in  making  something.  Most  boys  are  in  a  continual 
state  of  perplexity  in  trying  to  decide  whether  they  will 
be  blacksmiths,  carpenters,  or  shoemakers  when  they 
grow  up,  and,  for  all  such,  making  is  the  mode  of  expres- 
sion par  excellence. 

The  development  of  expression  by  means  cf  written  lan- 
guage should  be  coincident  with  that  of  the  other  modes. 
Through  its  peculiar  function,  it  acts  as  a  corrective  and 
check  upon  all  of  the  others.  It  is  very  important  that  it 
should  stand  in  proper  relation  as  to  amount  with  the 
other  modes  and  to  the  actual  demand  for  it.  Teachers 
frequently  err  by  trying  to  force  their  pupils  to  write  be- 
yond what  they  really  have  to  express.  Some  pupils  ap- 
pear to  talk  well,  but  write  poorly  ;  yet  it  may  be  that  the 
sum  total  of  all  their  "talk  "  actually  expresses  no  more 
than  the  little  they  write.  Again,  too  high  an  estimate 
is  often  placed  upon  what  the  pupil  really  sees,  and  con- 
sequently there  is  a  feeling  of  disappointment  at  the 
amount  of  the  written  work.  Rationally  employed,  written 
expression  is  the  most  valuable  adjunct  to  science  work. 

Although  there  seems  to  be  a  somewhat  definite  order 
of  development  for  the  different  modes  of  expression,  yet 
when  once  properly  begun  they  should  all  be  carried 
forward  in  due  proportion  throughout  the  entire  course. 
If  faithfully  done,  the  so-called  crudities  and  blotches  of 
the  first  grade  will  become  tasteful  products  in  the  eighth. 

The  subject  matter  in  science  work  presents  itself 
broadly  under  three  heads:  the  study  vt  function,  the  study 
of  form,  and  the  study  of  the  mutual  relations  between 
function  and  form.  These  divisions  at  once  suggest  to 


24  NATURE   STUDY. 

the  thoughtful  teacher  a  proper  grouping  of  the  modes 
of  expression.  Evidently,  those  which  best  accompany 
the  study  of  function  are  oral  language  and  written  lan- 
guage, and  to  a  less  important  extent  what  has  been  in- 
cluded tinder  gesture.  The  other  modes  are  not  barred, 
however,  since  one  may,  by  a  drawing,  or  in  a  clay  model, 
show  how  a  squirrel  holds  a  nut;  but  they  are  hardly  to 
be  considered  the  initial  modes  of  expression  for  such  a 
fact. 

In  the  study  of  form  almost  any  of  the  remaining 
modes  are  more  appropriate  in  the  beginning  than  either 
oral  or  written  language.  The  particular  form  must  be 
determined  by  the  one  who  makes  the  study — not  by  the 
teacher.  It  is  a  fundamental  mistake  for  a  teacher  to 
say  to  his  class,  "We  will  model  this,"  or  "We  will  paint 
that,"  or  "We  will  draw  the  other."  The  substance  of 
the  real  question  which  should  be  proposed  is,  "  What 
do  you  see  about  this,  or  what  can  you  find  out  about  it, 
and  how  will  you  tell  it  ?  "  When  the  teacher  dictates 
"Draw,"  "Paint,"  or  "Model,"  he  must  run  the  risk 
either  of  telling  the  pupil  to  represent  what  he  does  not 
see  or  understand,  or  else  he  is  forced  into  the  contra- 
dictory position  of  pointing  out  to  him  the  very  thing  he 
should  discover  for  himself  in  order  that  he  may  repre- 
sent it.  This  logically  and  actually  destroys  the  real 
point  of  the  lesson,  so  far  as  science  is  concerned,  and 
reduces  it  to  the  level  of  a  lesson  in  dead  color  and 
dumb  form.  The  pupil  cannot  express  what  he  does  not 
see,  and  he  must  express  what  he  does  see  through  what 
is  to  him  the  most  natural  and  appropriate  channel.  For 
example,  in  beginning  the  study,  to  ask  a  child  to  model 
a  brightly  colored  butterfly  is  to  outrage  his  every  sense 
of  fitness  ;  while  to  expect  him  to  either  paint  or  model 


EXPRESSION.  25 

with  great  enthusiasm  a  long-legged,  angular  grasshopper, 
is  vanity  of  vanities.  Full  expression  of  thought  will 
naturally  involve  more  than  one  mode,  but  there  is  de- 
cidedly a  right  and  a  wrong  place  at  which  to  begin. 

The  thoughts  which  come  into  the  mind  as  it  contem- 
plates the  mutual  adaptations  of  the  different  parts  of 
nature  to  each  other,  and  their  relations  to  the  whole 
are,  in  their  suggestions  of  infinite  law,  the 'loftiest  that 
can  possess  the  human  soul.  The  full  expression  of  these 
conceptions,  involving  the  highest  relations  of  man  to 
man,  rises  to  the  plane  of  fine  art.  Embalmed  in  verse,  or 
picture,  or  song,  or  chiseled  stone,  it  will  to  future  gen- 
erations mirror  forth  the  best  and  purest  thoughts  of  this 
age. 


PRACTICAL  HINTS  TO  THE  TEACHER. 


In  acting  upon  the  suggestions  in  the  following  lessons, 
it  is  essential  that  the  teacher  should  understand  the 
spirit  and  purpose  of  the  book.  Recognizing  the  fact 
that  most  teachers  find  themselves  unprepared  in  the  sub- 
ject matter  of  elementary  science,  the  book  has  been 
written  with  a  view  to  guiding  them  in  their  study  so  that 
they  may  acquire  some  of  the  necessary  knowledge  by 
actual  work,  and  not  with  the  intention  of  pouring  out  a 
mass  of  so-called  facts  for  them  to  memorize.  Teachers 
can  never  equip  themselves  for  this  work  by  reading 
alone  ;  if  that  were  possible,  the  requisite  preparation 
could  be  quickly  made  and,  with  a  market  well  supplied 
with  interesting  reading  books,  it  would  have  been  done 
long  ago.  The  main  trouble  is,  not  that  the  teacher's 
mind  is  so  barren  of  facts,  but  that  he  lacks  the  scien- 
tific habit  and  methods  of  study.  These  can  only  be  ac- 
quired by  the  exercise  of  the  greatest  patience,  on  the 
teacher's  part,  in  solving  for  himself  some  of  the  simple 
problems  presented  so  profusely  by  nature  on  every 
hand.  Under  every  division  of  the  subject  it  has  been  the 
aim  to  present  two  or  three,  sometimes  more,  leading 
topics  which  the  teacher  should  assist  the  pupils  to  work 
out  to  the  limits  of  their  capacity  by  careful  observation. 
Every  recitation  in  the  school-room  must  be  preceded  by 
lessons  in  actual  observations,  enough  of  which  must  be  de- 
manded from  every  pupil  to  give  him  a  basis  for  his  reason- 

26 


PRACTICAL  HINTS  TO  THE  TEACHER.  27 

ing.  A  most  pernicious  habit,  and  one  very  easily  ac- 
quired, is  that  of  asking  a  pupil  a  question  which  will  start 
him  to  guessing,  thus  deceiving  himself  into  the  belief  that 
he  is  actually  reasoning.  As  a  mere  "  Question  and  An- 
swer Book,"  this  book  must  inevitably  fail,  since  that  is  at 
utter  variance  with  its  purpose.  The  interrogative  rather 
than  the  declarative  form  has  been  adopted  because  it  has 
been  found  a  little  easier,  by  the  former  means,  to  carry  the 
thread  of  a  thought  through  several  suggestions.  In 
some  cases  one  question  suggests  the  thought  of  a  topic  ; 
in  others  several  questions  are  asked  for  the  same  purpose. 

The  teacher's  ingenuity  will  be  continually  taxed  to 
furnish  new  devices  adapted  to  the  correct  development 
of  a  topic,  which  will  also  be  properly  subject  to  his  own 
peculiar  circumstances  and  conditions.  The  latter  are 
not  the  same  for  any  two  teachers  ;  and  the  fact  that  this 
will  modify  the  treatment  of  any  question  is  one  that,  first 
of  all,  must  be  recognized  and  acted  upon. 

In  approximating  what  the  teacher  should  have  in  mind 
in  the  preparation  for  each  lesson  to  be  given,  the  follow- 
ing outline  is  submitted  as  a  guide  : 

I.  PLAN  FOR  EACH  LESSON. 

A.  Knowledge  of  Subject- Matter. 

1.  By  direct  observation. 

(a)  What  can  be  seen  in  a  field-lesson  ? 

(b)  What  can  be  collected  by  individual  pupils  ? 

(c)  What  can  the  pupils  make  ? 

2.  What  reading  belongs  legitimately  to  the  prep- 
aration ? 

3.  The    adaptation    to   the    pupils'   and   teachers' 

conditions. 

4.  The  adaptation  to  the  age  and  capabilities  of 

the  pupils,  /.  e.,  to  the  grade. 


28  NATURE   STUDY. 

5.  What  is  the  length  of  time  which  should  be  de- 
voted to  the  preparation  of  the  lesson  ? 

B.  What  modes  of  expression  should  be  used  ? 

,.  Oral  language  ?          j.  what  tiye  readi      ? 

2.  Written  language  ?    ) 

3.  Painting. 

4.  Modeling. 

5.  Drawing. 

6.  Making. 

C.  How  is  the  lesson  related  to  other  subjects  ? 

1.  Reading. 

2.  Number. 

3.  History  and  literature. 

4.  Language. 

II.    HINTS    TO    BE    OBSERVED    IN    GIVING    THE    LESSON  ? 

1.  Have  a  reason  clearly  in  mind  for  giving  every 
lesson.     Seek  for  this  in  the  relation  of  the  sub- 
ject to  the  child. 

2.  Have  a  reason  clearly  in  mind  for  the  way  in 

which  the  lesson  is  presented.  Seek  for  this 
in  a  study  of  the  laws  which  govern  tJie  growth 
of  the  child's  mind. 

3.  Plan  only  for  such  work  as  the  pupils  can  do 

for  themselves,  or,  at  least,  take  the  leading 
part  in  doing. 

4.  Place  the  child  directly  in  contact  with  nature 

under  normal  conditions. 

5.  Begin  with  something  which  is  really  a  part  of 

the  pupil's  experience — not  with  something 
which  you  have  to  tell  him. 

6.  Accept,  as  good,  only  such  results  as  indicate 

honesty  of  purpose  and  growth  of  mind. 

7.  Be  faithful,  and  bide  your  time. 


Each  season  of  the  year  has  its  own  peculiar  influence 
upon  living  things,  animal  and  plant.  It  is  therefore 
most  convenient  and  certainly  most  interesting  to  study 
each  phase  of  life  in  the  appropriate  season,  inasmuch  as 
one  may  then  more  easily  trace  the  various  phenomena 
observed  in  living  things  to  the  forces  in  nature  which 
cause  them.  As  the  sun  rises  later  and  later,  and  sets 
earlier,  sinking  still  lower  in  the  southern  sky,  and  the 
air  now  and  then  steals  down  upon  us  with  an  edge  ac- 
quired in  northern  snow-fields,  animal  creation  takes  the 
hint  and  prepares  for  the  inevitable  and  impending  change. 
The  birds,  the  young  ones  that  have  never  seen  a  flake  of 
snow,  as  well  as  the  veterans  of  experience,  in  good  time 
gather  themselves  together,  and  within  a  few  hours  are 
safe  in  another  zone.  Their  luckless  relatives,  the  rep- 
tiles, appear  with  less  and  less  frequency,  and,  finally,  in 
the  lowest  depths  of  their  burrows  give  themselves  up  to 
a  stupor  that  seems  more  like  death  than  sleep.  The 
winged  insect  hosts,  battered  and  bedraggled,  demoralized 
by  the  gayeties  of  the  season,  until  mere  wrecks  of  their 
former  selves,  for  most  part  stiffen  and  die  where  they 
are,  rather  than  give  up  one  moment  of  present  pleasure 
to  thoughts  for  the  future,  or  desert  the  fields  that  may 
have  seemed  to  them  to  promise  endless  enjoyment. 
Others,  apparently  as  much  by  chance  as  through  design, 
are  saved  from  such  fate  by  finding  a  lodgment  in  cracks 
in  old  walls,  in  decaying  logs,  under  stones,  and  in  holes 


36  NATURE    STUDY.  [September 

in  the  ground.  Other  creatures,  too  plucky  to  leave,  and 
refusing  to  waste  the  winter  in  sleep,  seek  to  cut  down 
living  expenses  in  the  time  of  dearth  by  taking  on  an 
extra  thickness  of  fur  or  hair,  and  by  packing  away  great 
layers  of  fat  in  times  of  plenty.  In  the  streams  the 
changes  are  not  less  marked.  Chilled,  and  deprived  of 
their  insect  food,  the  fishes  seek  the  bottom  and  hide  in 
recesses  among  the  rocks.  The  "  craws  "  withdraw  them- 
selves into  their  dens  in  the  mingled  sand  and  gravel, 
while  the  tadpoles  wriggle  themselves  under  leaves  and 
grass  on  the  sides  and  in  the  bottom  of  the  ponds,  and 
for  a  time  their  froggish  ambition  is  stayed.  Nor  are 
these  influences  unfelt  among  human  kind.  Despite  the 
fact  that  our  natural  appetites  are  becoming  somewhat 
depraved  by  the  fruits  and  various  vegetables  which 
modern  means  of  rapid  transit  make  possible  for  us  in 
January,  we  still  are  in  a  measure  moved  by  instincts 
similar  to  those  which  control  our  humble  brethren,  the 
brutes.  The  gradual  change  in  color,  texture,  and  thick- 
ness of  clothing,  and  the  modification  in  our  appetites, 
are  signs  the  youngest  school-child  may  note,  and  which 
he  will  be  interested  to  understand.  These  changes,  in 
the  total  amounting  to  a  revolution  in  a  living  creature's 
mode  of  life,  take  place  every  year  so  silently  and 
almost  imperceptibly  as  to  scarcely  attract  attention  of 
people  in  general ;  nor  does  even  the  keenest  observer 
yet  fully  understand  the  causes  by  which  they  have  been 
wrought.  To  lead  to  a  careful  study  of  these  phenomena, 
in  which  we  ourselves  are  involved  more  deeply  than  might 
at  first  be  suspected,  by  teaching  the  child  to  live  in  close 
and  loving  communion  with  nature  about  him,  is  the 
highest  duty  of  the  teacher.  Not  by  set  lessons  in  the 
recitation-room,  nor  by  dissections  in  the  laboratory 


September]  ZOOLOGY.  $t 

alone,  can  this  be  accomplished  ;  before  these  can  reveal 
the  depths  of  their  meaning  he  must  study  LIFE  in  at 
least  some  of  its  myriad  forms,  and  know  something  of 
the  forces  that  produce  it,  and  conditions  under  which 
it  exists. 

The  teacher  should  select  from  the  following  topics  a 
few  of  those  which  are  best  suited  to  the  conditions  for 
study  that  environ  the  pupils.  A  thicket,  or  even  a  single 
tree,  will  generally  enable  the  pupils  to  study  the  topics 
on  birds. 

To  collect  insects,  the  pupils  should  be  provided  with 
small  nets.  Make  these  by  bending  a  wire,  about  No.  8 
or  No.  9,  into  a  hoop  six  inches  in  diameter,  and  then 
twisting  the  ends  together  for  two  or  three  inches  to  form 
a  handle.  This  may  be  thrust  into  a  hole  made  in  the 
end  of  an  old  broom-stick  for  a  longer  handle,  if  desired. 
Make  the  net  about  eighteen  inches  deep,  using  mosquito- 
netting  or  cheese-cloth.  A  little  practice  will  enable  the 
pupils  to  get  the  insect  and  transfer  it  from  the  net  to  the 
poison  bottle  (see  Zoology  for  April,  under  Insects)  with- 
out marring  them.  Collect  not  only  those  insects  which 
are  to  be  seen  flying  about,  but  also  those  that  may  be 
obtained  by  jarring  the  branches  of  a  shrub  or  tree  over 
the  open  net.  A  great  number  may  also  be  easily  obtained 
by  placing  in  convenient  places  shallow  vessels  containing 
sweetened  water  or  vinegar.  Naturalists  sometimes  smear 
tree  trunks  with  a  mixture  of  beer  and  molasses  for  the 
same  purpose. 

In  the  lower  grades,  one  or  two  poison  bottles  will  suf- 
fice for  each  room.  In  the  grammar  grades  each  pupil 
should  be  encouraged  to  place  a  poison  bottle  among  the 
material,  which  he  should  be  expected  to  collect  and  keep 
for  his  own  use  during  the  year.  The  primary  pupils 


32  NATURE   STUDY.  September 

will  make  far  more  use  of  the  living  insects  than  of  the 
dead  ones  ;  but  in  the  upper  grades  the  study  will  natur- 
ally be  more  detailed,  and  dead  insects  will  be  required. 
In  order  to  observe  the  work  of  earthworms  in  plug- 
ging their  burrows,  select  some  place  where  they  may 
easily  obtain  leaves  as  they  fall  from  the  trees.  It  is 
astonishing  to  find  how  many  leaf-stalks  are  sometimes 
pulled  into  one  burrow. 

BIRDS. 

1.  Are  any  birds  nest-building  or  laying  eggs  at  present? 

2.  Can  you  distinguish  the  young  from  the  old  ?   Which 
parent  do  they  most  resemble  ? 

3.  Do  the  young  ones  sing  ?     Are  they  still  under  the 
care  of  the  old  birds  after  they  have  learned  to  fly  ? 

4.  Have  any  disappeared  that  were  noticed  during  the 
summer  ? 

The  times  of  migration  vary  somewhat  with  the  season, 
within  rather  narrow  limits.  The  birds  should  be  watched 
closely  during  this  month  and  the  next. 

5.  What   influences  can   you   discover  at   this  season 
which  would  cause  the  birds  to  migrate  ? 

INSECTS. 

Nothing  is  more  wonderful  and  interesting  than  the 
great  variety  of  insect  life  which  may  be  studied  at  this 
time.  Some  one  has  remarked  that  no  region  on  the 
globe  has  proven  so  inhospitable  that  some  insect  cannot 
adapt  itself  to  it  ;  nor  has  any  other  living  creature  suc- 
ceeded in  doing  anything  which  the  insects  do  not 
imitate. 

i.  In  what  different  places  have  you  found  insects? 
Look  on  the  leaves  of  plants,  under  boards,  logs,  stones, 


September]  ZOOLOGY.  33 

etc.,  in  old  walls,  in  cellars,  in  cupboards,  in  the  grass,  on 
the  flowers,  and  in  holes  in  the  ground. 

2.  What  are  the  chief  differences  between  those  that 
spend  their  time  in  the  open  air  and  those  that  live  under 
stones,   etc.,    as,    for   example,    between   butterflies    and 
beetles  ? 

3.  What  insects  can   you  find  that  must  have  liquid 
food  ?     What  ones  take  solid  food  ? 

4.  Where  do  butterflies  get  their  food  ?     Can  you  tell 
certainly  if  they  get  it  from  flowers  ? 

5.  Do  they  visit  all  kinds  of  flowers?     Is  their  food 
solid  or  liquid  ? 

6.  If   the    flower    furnishes    their    food    where    is    it 
stored  ? 

7.  What  means  does  the  butterfly  employ  in  examining 
the  flower  ?     What  does  it  do  with  the  organ  when  not  in 
use  ? 

8.  Does  the  butterfly  store  food  for  the  future  ? 

9.  How  does  it  cling  to  the  plant  ? 

10.  How  does  it  dispose  of  its  wings  when  at  rest  ? 

11.  Compare   the    upper   and    under    surfaces    of    the 
wings  ;  which  render  it  more  conspicuous. 

12.  Compare  the  color  of  butterflies  with  that  of  the 
flowers  they  visit. 

13.  How  does  the  character  of  a  butterfly's  flight  differ 
from  that  of  a  bird  ?     How  can  you  account  for  it  ? 

14.  Is  the  peculiar  flight  of  advantage  or  disadvantage 
to  it  ? 

15.  Which  has  relatively  the  greater  wing  surface,  the 
butterfly  or  bird  ?     Which  is  the  stronger  flyer  ? 

16.  Compare  the  fore  and  hind  wings  ;  is  the  venation 
the  same  in  both  ?     Is  it  the  same  in  the  right  and  left 
wings  of  the  same  pair  ? 


34  NATURE   STUDY.  [September 

17.  Of  what  use  are  the  legs?     Compare  and  contrast 
the  different  pairs. 

1 8.  In  what  order  do  they  move  when  walking  ?     What 
way  do  they  bend  at  the  joints  ?    Why  are  so  many  joints 
needed  ? 

19.  How  are  they  arranged  during  flight  ? 

20.  In  what  directions  can  the  butterfly  see  you  ap- 
proach ? 

21.  Where  are  its  eyes?     Can  it  turn  its  head  ? 

22.  Can  it  move  its  eyes  without  moving  its  head  ? 

23.  Are  the  eyes  sensitive  ?     Can  you  tell  if  it  has  the 
sense  of  feeling  ? 

24.  Has  it  the  sense  of  smell  and  of  hearing  ?     Does  it 
make  any  sound  ?     Does  it  breathe  ? 

25.  Are  they  social  ?     Do  they  build  nests  ? 

26.  Do  they  prefer  sunlight  or  shade?     Where  do  they 
stay  during  the  night  ? 

27.  Are  any  eggs  to  be  found  at  this  season  ? 

28.  Can  you  tell  the  male  from  the  female  ?     Can  you 
see  any  reason  for  difference  in  color  ? 

Collect  larvae  (caterpillars)  of  different  kinds  and  put 
them  in  small  boxes  covered  with  light  netting.  Feed  them 
with  the  leaves  of  the  plant  upon  which  they  were  found. 

In  a  way  similar  to  the  above  outline,  study  grass- 
hoppers, beetles,  bees,  and  flies. 

WORMS. 

1.  Note  the  manner  in  which  worms  plug  their  burrows 
with  leaves,  etc.     Do  they  eat  them  ? 

2.  Are  the  castings  as   numerous  as  in  the  summer 
months  ? 

3.  Can  you  find  sticks  or  straws  or  other  material  that 
has  been  drawn  into  their  burrows  during  the  season  ? 


September]  ZOOLOGY.  35 

TADPOLES. 

r.  In  what  stages  of  development  are  tadpoles  to  be 
found  ? 

2.  How  do  they  breathe?     Look  sharply  for  a  small 
hole  on  one  side  behind  the  mouth.     Is  it  always  on  the 
same  side  ? 

3.  What  is  their  food  ? 

4.  Do  they  venture  out  on  the  land  ? 

5.  What  enemies  do  they  have  ? 

BOOKS  FOR  REFERENCE.  Humboldt  Library:  Nos.  115  and  116. 
No.  99,  Nature  Studies,  chapter  on  Birds  of  Passage.  No.  33, 
Vignettes  from  Nature,  chapteis  iv,  xiv.  No.  6;,  Distribution  of 
Life.  No.  92,  Formation  of  Vegetable  Mold.  No.  26,  The  Evolu- 
tionist at  Large,  chapters  x,  xiv. 


Botany 

Introduce  the  lessons  on  plants  with  outdoor  observa- 
tions both  with  the  class  as  a  whole,  if  possible,  and  by 
requiring  individual  work  out  of  school  hours.  Indicate 
the  points  of  a  lesson  a  sufficient  length  of  time  before 
the  recitation  to  give  the  pupils  opportunity  to  make  the 
proper  observations.  Only  a  small  part  of  a  plant's  life- 
history  is  revealed  to  us  in  a  single  month,  but  in  many 
cases  the  entire  cycle  of  its  life  is  shown  in  the  course  of 
a  year.  The  study  should  so  proceed,  therefore,  as  to  re- 
veal the  history  as  a  connected  whole  when  the  year  is 
ended.  Facts  are  rarely  interesting  unless  seen  in  their 
proper  relations  to  each  other.  All  drawings,  paintings, 
models  in  clay  as  far  as  possible,  and  written  work,  should 
be  carefully  preserved  so  that  additions  may  be  made  to 
them  in  the  different  seasons.  Sheets  of  paper  of  a  size 
8^x11  inches,  both  for  writing  and  drawing,  will  be  found 
convenient  for  pupils  of  grammar-school  age,  while  such 
sheets  cut  in  two  crosswise  will  suit  those  in  the  primary 
grades.  These  may  be  preserved  by  the  pupil  in  a  port- 
folio, which  he  can  easily  construct  for  himself  out  of 
cardboard.  Drawing  paper  of  the  above-mentioned  size 
is  large  enough  to  admit  of  the  representation  of  the  most 
prominent  features  of  a  plant's  history.  The  drawings 
and  paintings  made  in  the  fall,  of  leaf,  twig,  fruit,  etc., 
should  be  so  placed  as  to  admit  representations  of  the 
germinating  seed  and  young  plant  to  be  placed  beside 
them  in  the  spring.  Each  sheet  will  thus  present  a  whole, 

36 


September]  BOTANY.  37 

and  the  pupil  will  almost  unconsciously  acquire  the  habit 
of  bringing  all  individual  facts  observed  into  proper  rela- 
tion with  each  other. 

It  will  be  a  revelation  to  those  botanists  who  are  book- 
bred,  as  well  as  to  the  children,  to  find  that  there  is  not  a 
day  of  the  whole  growing  season  in  which  some  seeds,  be- 
lated for  one  reason  or  another,  are  not  trying  to  germ- 
inate. Germination  of  seeds  is  associated  mostly  with 
spring-time,  because  the  seeds  that  do  get  a  fair  start  at 
that  time  are  the  ones  that  become  so  conspicuous  later 
in  the  season  as  to  almost  obscure  the  luckless  ones  that 
failed  to  make  an  early  beginning.  Still,  the  latter  do  not 
cease  trying,  and  at  the  first  favorable  opportunity  they 
put  forth  their  energies,  only  to  have  a  useless  growth, 
nipped  by  an  untimely  frost,  or  smothered  out  by  their 
hardier  companions.  One  finds  it  difficult  to  make  this 
lavish  extravagance,  and  apparent  waste  of  vital  force, 
conform  to  human  ideas  of  economy. 

Make  the  function  the  central  thought  in  the  study  of 
fruits,  and  introduce  the  study  of  the  parts  with  their 
names  as  needed  to  explain  it.  With  the  child,  the  func- 
tion of  fruit  has  been  fulfilled  when  it  becomes  an  article 
of  food  for  himself.  There  are,  indeed,  older  people  who 
see  no  further.  Yet  with  the  proper  suggestive  instruc- 
tion, the  colors,  the  edibility,  the  hooks  and  prickles,  and 
the  various  sails  and  wings  with  which  fruits  are  provided 
will  reveal  such  a  refinement  of  means  to  an  end  that  it 
seems  almost  impossible,  at  first,  to  account  for  them  ex- 
cept on  the  supposition  of  intelligence  in  the  plant.  Still 
further  study  gives  the  pupil  a  glimpse  of  the  final  conflict 
of  the  year  in  the  great  struggle  among  the  plants  for 
supremacy.  Observation  will  show  the  effect  of  the 
strong  early  growth  upon  the  maturing  seeds ;  they  are 


38  NATURE   STUDY.  [September 

usually  better  equipped  in  every  way  than  the  unfortu- 
nates of  later  growth.  From  such  studies  the  pupil's 
notions  of  how  the  world's  life  has  come  to  be  what  it  is, 
and  of  the  enormous  length  of  time  involved,  will  be 
broadened  and  strengthened. 

1.  Can  you  find  any  seeds  germinating  at  this  time  ? 
Are  they  of  this   year  or  last  year's  growth  ?     Can  you 
find  any  seeds  in  the  ground  that  have  lain  there  during 
the  summer  without  germinating  ?     If  so,  can  you  account 
for  it  ? 

2.  Have  plants  finished  their  growth  for  this  season  ? 
How  can  you  tell  ?     Make  measurements  for  at  least  two 
weeks  before  deciding  as  to  the  growth  of  the  plants. 

3.  What  do  these  growths  consist  in  ?     What  ones  are 
permanent,  what  probably  for  the  season  only  ? 

4.  Compare  by  measurement  the  lengths  added  to  the 
twigs  of  different  trees.     Have  the  old  ones  added  as 
much  as  the  young  ones  ? 

5.  On  what  part  of   the  tree  have  the  longest  twigs 
grown  ? 

6.  Can  you   notice  any  difference  in  this  respect  be- 
tween the  north  and  south  sides  of  a  tree  ? 

Do  not  trust  to  single  observations  for  the  answer  to 
these  questions.  Take  the  mean  or  average  of  at  least 
ten. 

7.  Are  the  new  twigs  undergoing  any  change  at  this 
time  ? 

8.  Examine  closely  the  leaves  ;  on  a  branch  bearing 
fifty.  How  many  do  you  find  free  from  insect  depredations? 
In  how  many  ways  have  they  been  used  by  animals  ? 

9.  Do  any  plants  appear  to  be  the  especial  prey  of  in- 
sects ? 

10.  What  ones  seem  to  be  freest  from  them  ?     Can  you 


September]  BOTANY.  39 

see  any  reason  for  it  ?     Give  at  least  two  weeks  for  ob- 
servations. 

11.  In  what  way,  if  any,  can  you  see  the  effects  of  the 
weather  of  this  month  upon  vegetation  ?     Is  it  promoting 
growth  or  retarding  it  ?     Is  it  tending  to  mature  the  young 
parts  or  to  prevent  their  maturing  ? 

12.  What  fruits  are  ripening  this  month  ?    Write  a  list 
of  all  you  have  seen. 

Make  a  number  of  envelopes  about  3x4  inches  out  of 
manilla  paper,  and  collect  and  preserve  in  them  seeds  of 
all  the  different  kinds  of  plants  as  they  ripen.  These  will 
be  used  in  the  spring  when  studying  germination.  A 
great  variety  is  then  desirable,  and  cannot  at  that  time  be 
easily  obtained. 

13.  How  do  you  account  for  the  brilliant  colors  of  some 
fruits,  as  in  the  case  of  the  berries  ? 

14.  What  color  is  most  common  amongst  ripened  fruits  ? 
Why  is  it  so  ?     What  color  is  next  ? 

15.  Are  there  any  plants  whose  fruits  do  not  change 
color  in  ripening  ?     What  other  changes  take  place  while 
ripening? 

16.  What  color  prevails  in  unripe  fruit  ?     Can  you  see 
a  reason  for  it  ? 

17.  What  parts  of  the  flower  become  the  fruit  ?     Com- 
pare as  many  different  kinds  as  can  be  found. 

18.  Do  they  all  have  any  one  thing  in  common  ? 

In  a  strict  botanical  sense  a  fruit  is  a  "  ripened  ovary 
and  its  contents."  In  addition  to  this  there  are  fre- 
quently present  other  parts  of  the  flower,  which  are  so 
modified  as  to  assist  directly  or  indirectly  in  the  distribu- 
tion of  the  seed.  Sometimes  these  accessory  parts  are  the 
most  prominent  features  and  are  commonly  regarded  as 
the  fruit  itself.  The  typical  ovary  wall,  as  a  whole  known 


40  NATURE   STUDY.  [September 

as  the  pericarp,  is  made  up  of  three  layers  ;  an  outer, 
called  the  exocarp  or  epicarp,  an  inner,  called  the  endo- 
carp,  and  one  between  called  the  mesocarp.  When  the 
latter  is  fleshy,  it  is  called  the  sarcocarp.  The  seed  has, 
besides,  its  own  coverings  or  coats,  which  closely  invest 
the  embryo.  The  chamber  containing  the  seed  is  the 
cell  ;  often  there  are  several  of  these  in  one  ovary,  in 
which  case  the  partitions  are  called  dissepiments.  The 
part  of  the  ovary  to  which  the  seeds  are  attached  is  called 
the  placenta.  This  is  axial  if  passing  through  the  ovary 
as  an  axis,  central  if  standing  stalk-like  in  the  middle  of 
the  ovary,  basal  when  the  seeds  are  clustered  about  a 
point  in  the  bottom  of  the  ovary,  and  parietal  when  the 
seeds  are  attached  to  the  ovary  wall.  The  classification 
of  fruits  is  based  upon  the  different  development  of  these 
parts. 

19.  Select  a  number  of  fleshy  fruits  for  study,  such  as 
the  grape,  tomato,  cucumber,  melon,  squash,  and  apple. 
In  what  respects  are  these  all  alike  ?     By  drawings  or 
paintings,  represent  the  different  parts  of  these  fruits,  to- 
gether with  the  leaf  and  twig  of  the  plant. 

20.  Can  you  see  any  reason  for  the  different  colors  ? 

21.  Why  is  purple  a  good  color  for  grapes  when  ripe? 
How  would  red  or  yellow  do  ? 

Keep  in  mind  the  wild  state  of  the  fruits  in  trying  to 
account  for  their  characteristics. 

22.  On  what   part   of   the   plant  are   the  fruits  most 
highly     colored  ?     Are    they    equally    colored     on    all 
sides  ? 

23.  Of  what  advantage  is  it  to  certain  fruits  to  acquire 
a  hard  or  tough  rind  when  ripening  ? 

24.  What  parts  of  these  fruits  have  been  most  devel- 
oped by  cultivation  ? 


September]  BOTANY.  4* 

25.  Select  and  in  the  same  way  study  the  stone  fruits, 
such  as  the  peach,  plum,  and  apricot. 

26.  What  parts  of  the  flower  form  the  fruit  in  each 
case  ?     Make  drawings  and  paintings  of  the  structure. 

27.  How  has  cultivation  affected  the   plants  bearing 
these  fruits  ?     Does  it  tend  to  make  them  more  or  less 
hardy  ? 

28.  Where  do  these  fruits  grow  in  their  wild  state  ? 

29.  Are  the  locations  where  they  flourish  under  culti- 
vation similar  to  those  where  they  grow  wild  ? 

30.  Which  of  the  fruits  studied  are  most  preyed  upon 
by  insects  ?    Which  the  least  ? 

31.  What   animals   eat   the   ripened  fruit  in  its  wild 
state  ? 

BOOKS  FOR  REFERENCE.  Humboldt  Library  :  Nos.  H5andn6, 
Darwinism,  by  Alfred  Russel  Wallace  ;  chapters  on  Variation  and 
Colors  of  Plants.  No.  26,  The  Evolutionist  at  Large,  chapters  ii 
and  ix.  No.  64,  The  Distribution  of  Life.  Origin  of  Cultivated 
Plants  (International  Scientific  Series).  Field  and  Forest  Botany  ; 
Gray. 


In  the  study  of  Physics  the  most  important  conception 
for  the  child  to  gain  is  that  concerning  the  nature  of  the 
forces,  exclusive  of  those  termed  chemical,  which  act 
about  him  and  upon  him,  in  a  great  measure  condition- 
ing his  existence.  Experiments  illustrating  the  action  of 
these  forces,  as  exhibited  in  the  many  varied  natural 
phenomena  of  rain,  snow,  frost,  dew,  clouds,  heat,  light, 
magnetism,  etc.,  together  with  the  general  principles 
underlying  mechanics,  may  be  performed  by  the  children, 
under  careful  supervision,  with  comparative  ease.  The 
idea  which  prevails  to  some  extent,  that  work  of  this  kind 
does  not  possess  the  interest  for  young  pupils  that  the 
study  of  animals  and  plants  does,  is  a  mistaken  one.  If 
the  experiments  are  properly  selected  they  will  not  fail 
to  absorb  the  attention,  for  the  reason  that  the  children 
will  be  able  to  see  the  cause  of  certain  vital  phenomena  that 
otherwise  could  not  be  understood.  An  error  often  made 
is  the  failure  to  impress  the  fact  that  an  experiment  is 
not  an  end  in  itself,  but  is  valuable  only  as  it  throws  light 
upon  some  phase  of  nature.  Expensive  apparatus  is  un- 
necessary ;  for  elementary  work  it  is  more  often  a  hin- 
drance than  a  help,  in  that  it  tends  to  distract  attention. 
A  little  ingenuity  on  the  part  of  teacher  and  pupil  will 
readily  supply  nearly  all  that  is  needed. 

LIGHT. 

i.  Place  in  a  window  where  the  direct  sunlight  will 
strike  it  a  small  glass  prism.  Near  it  on  the  side  next 

42 


September]  PHYSICS.  43 

the  sun  place  a  piece  of  cardboard  in  which  there  is  cut 
a  small  slit.  Let  the  sunlight  pass  through  the  opening 
and  strike  the  prism. 

A  prism  may  be  made  by  taking  three  strips  of  clear 
glass  of  equal  length  and  width,  and  placing  them  to- 
gether so  as  to  form  a  triangular  prism.  Cut  a  trian- 
gular piece  of  tin  half  an  inch  larger  than  the  end  of 
the  prism  and  bend  up  outside  so  as  to  form  a  bottom. 
Seal  all  the  seams  with  common  sealing  wax,  and  fill  with 
clear  water.  Place  on  a  support  in  the  window  and  turn 
it  until  the  spectrum  falls  upon  the  opposite  wall  or  some 
other  suitable  screen. 

2.  What   changes   does   the  prism   make  in  the  sun- 
light? 

3.  Are  the  colored  rays  in  a  straight  line  with  the  sun- 
light that  enters  the  prism  ? 

4.  Which  rays  are  nearest  to  a  straight  line  with  it  ? 
Which  are  farthest  from  it  ? 

5.  How  many  colors  can  be  distinguished  ? 

6.  Place  a  piece  of  white  paper  in  the  different  rays  ; 
what  color  does  it  appear  to  be  ? 

7.  Make  use  of  these  colors  in  describing  the  tints  of 
fruits,  insects,  and  autumn  leaves. 

MAGNETISM. 

Magnetize  a  large  knitting  needle  by  rubbing  it  over 
the  poles  of  a  magnet,  and  thrust  it  through  a  cube  of 
wood  or  small  cork  half  an  inch  in  diameter,  so  that  the 
needle  will  balance  upon  it.  Attach  a  strong  silk  thread 
to  this  and  suspend  it  from  the  ceiling  or  other  support, 
where  it  will  not  be  disturbed  by  air  currents.  Each 
pupil  may  make  his  own  magnetic  needle,  using  a  sewing 
needle  for  the  purpose. 


44  NATURE   STUDY.  [September 

1.  When  suspended,  what  direction  does  the  needle 
assume  ? 

2.  Will  it  remain  in  any  other  position  ? 

3.  Find,  before  magnetizing,  the  exact  point  at  which 
the  needle  balances  ;  when  magnetized  and  suspended 
from  the  point,  is  the  needle  horizontal? 

The  variation  from  the  horizontal  is  known  as  the  dip 
of  the  needle.  This  increases  gradually  northward  to  a 
point  near  Boothia  Gulf,  when  it  stands  vertical.  This  is 
called  the  North  Magnetic  Pole. 

4.  Is  each  end  of  the  needle  attracted  by  both  poles  of 
the  magnet  ?     The  north  end  of  the  needle  is  called  its 
positive  pole,  the  south  end  the  negative  pole. 

5.  Which  pole  of  the  needle  does  the  north  pole  of  the 
magnet   (usually  marked  N)   attract  ?     Which  does   the 
south  pole  attract  ? 

A  compass  consists  of  a  needle  magnetized  and  deli- 
cately poised  on  a  pivot,  so  as  to  turn  freely,  and  pro- 
tected by  a  case  provided  with  a  glass  top.  Small 
magnets  may  now  be  purchased  for  one  cent  each. 

6.  How  many  useful  purposes   can   you   think  of  to 
which  the  compass  may  be  devoted  ? 

7.  When  would  the  needle  in  the  room  be  the  most  use 
to   you  ?     What   two   directions   does   it   give  directly  ? 
What  two,  indirectly  ? 

8.  Make  use  of  this  needle  in  determining  the  direction 
of  the  wind  ;  of  the  road   home  ;  the  direction   toward 
different  places,  buildings,  etc.,  in  the  neighborhood,  etc. 

Use  the  magnets  in  testing  for  iron  and  steel  amongst 
metals. 

In  most  places  the  needle  does  not  point  toward  the 
true  north  ;  east  of  a  line  running  through  Wilmington, 


September]  PHYSICS,  45 

N.  C,  Charlottesville,  Va.,  and  Pittsburgh,  Pa.,  the  dec- 
imation from  the  true  north  is  toward  the  west  ;  west  of 
it  the  declination  is  toward  the  east. 

BOOKS  FOR  REFERENCES.     Humboldt  Library  :  No  i,  The  Earth 
a  Magnet.     No.  18,  Appendix.     An  elementary  lecture  on  Magnet- 


Chemistry 


FERMENTATION. 

By  means  of  a  large-sized  grater  reduce  a  considerable 
quantity  of  the  different  fruits  to  a  pulp.  Press  the  juice 
through  muslin  or  cheese  cloth  and  bottle  it.  When 
the  pupils  have  tested  the  juice  so  obtained  by  taste 
and  have  learned  how  it  is  obtained,  a  quart  of  sweet 
cider  divided  up  into  four  or  five  bottles,  and  allowed 
to  stand,  will  illustrate  the  changes  which  take  place 
during  fermentation.  The  different  conditions  under 
which  they  are  placed  will  reveal  those  most  favorable  to 
the  change. 

The  formation  of  hard  cider  is  due  to  what  is  called 
alcoholic  fermentation.  The  source  of  this  is  the  yeast 
plant,  which  in  its  growth  breaks  up  the  sugar  which  the 
juice  contains  into  alcohol,  carbonic  acid  gas,  and  small 
amounts  of  other  substances.  After  the  alcoholic  fer- 
mentation, the  souring  or  change  to  vinegar  is  due  to  the 
formation  of  acetic  acid  in  acetic  fermentation.  These 
changes  may  be  followed  and  noted  as  they  occur.  The 
teacher  should  be  particular  to  have  the  children  do  this 
work  in  a  neat  and  cleanly  manner  ;  otherwise  they  should 
not  do  it  at  all. 

1.  Note  carefully  the  taste  and  color  when  freshly  pre- 
pared. 

2.  Place  different  bottles  under  different  conditions  : 


September]  CHEMISTRY.  47 

some  corked,  others  open  ;  some  in   a  cool,  others  in  a 
warm  place,  etc. 

3.  Under  what  conditions  do  the  changes  occur  most 
rapidly  ? 

4.  Add  a  little  yeast  to  some  of  the  juice,  and  when 
fermentation  has  taken  place  it  will  be  ready  for  distilla- 
tion.    (See  Physics  for  October.) 

5.  Do  the  bubbles  which  rise  contain  air  ? 

6.  Test   by  lowering   into   a   half-filled   jar   a  lighted 
match  or  taper.     Does  it  behave  as  it  does  when  lowered 
into  air  ? 

7.  By  means  of  a  bent  glass  tube  through  the  cork  of 
a  bottle,  force  some  of  the  gas  into  some  lime  water. 
Note   the  change.     The  tests  with   the  flame  and  lime 
water  indicate  carbonic  acid  gas. 

8.  Can  you  account  for  the  cork  being  blown  from  a 
tightly  corked  bottle  while  fermentation  is  taking  place  ? 

9.  Is  the  liquid  remaining  in  the  bottle  after  fermenta- 
tion the  same  substance  that  was  there  before  it  took 
place  ?     How  can  you  tell  ? 

10.  The   change   which  has   taken   place   is  called  a 
chemical  change. 


flDeteorologp 


GENERAL   DIRECTIONS  AND   SUGGESTIONS. 

In  order  to  carry  out  successfully  the  work  under  this 
head,  it  is  necessary  that  the  pupils  make  daily  observa- 
tions for  themselves,  and  that  these  be  recorded  neatly  in 
some  systematic  manner,  so  that  summaries  can  be  readily 
made  from  which  correct  inferences  may  be  drawn.  For 
this  purpose  a  blank  form  has  been  prepared,  a  model  of 
which  is  given  on  another  page.  This  may  be  prepared 
by  each  pupil  himself,  and  should  be  on  a  sheet  about 
8^  by  1 1  inches.  One  such  sheet  will  contain,  without 
crowding,  a  month's  observations  and  summaries.*  An 
enlarged  form  of  the  blank,  sufficient  for  a  week's  record, 
should  be  drawn  upon  the  blackboard,  and  the  daily  ob- 
servations written  thereon  by  the  pupils.  To  save  time 
and  avoid  the  confusion  naturally  arising  from  the  vary- 
ing accuracy  in  different  observers,  it  is  better  to  assign 
the  work  to  a  different  pupil  each  day.  This  places  him 
subject  to  the  criticism  of  the  entire  class,  and  will  pro- 
mote carefulness  in  observation.  His  record,  however, 
should  not  be  changed  simply  because  it  does  not  agree 
with  that  of  some  one  else,  or  with  even  a  majority. 
Each  pupil's  work  must  stand  for  itself. 

*  Printed  blank  forms  of  this  Meteorological  record  have  been  pre- 
pared by  the  author,  and  have  been  embodied  in  a  notebook  for  gen- 
eral science  work. 

48 


September]  METEOROLOGY.  49 

Select  a  time  when  it  will  be  most  convenient  each  day 
to  make  the  record,  and  adhere  strictly  to  it.  It  may, 
of  course,  vary  within  certain  limits  ;  as,  for  example,  be- 
tween 2  and  3  P.  M.  To  get  data  of  greater  general  value, 
divide  the  school  into  three  divisions  and  assign  to  the 
first,  the  time,  say,  between  9  and  10  A.  M.;  to  the  second, 
an  hour  near  the  middle  of  the  day,  and  to  the  third  the 
last  hour.  The  average  for  each  day  can  then  be  found 
when  making  up  the  summary  for  the  week. 

Teachers  sometimes  make  the  serious  mistake  of  de- 
manding strict  uniformity  in  the  records  made  by  the 
pupils.  Such  uniformity  could  hardly  be  expected  from 
a  trained  body  of  scientific  observers,  much  less  must  it 
be  looked  for  among  children  who  are  beginning.  It  is 
absolutely  fatal  to  the  good  which  may  come  of  the  work 
to  the  individual  pupil,  if  the  teacher  falls  into  the  very 
common  habit  of  deferring  to  two  or  three  of  the  brightest 
ones  respecting  certain  observations,  and  then  requiring 
the  rest  to  abide  by  their  decision.  Better  far  let  each 
pupil  record  his  own  observation,  without  discussion  or 
reference  to  what  his  neighbor  is  doing,  though  you  may 
know  at  the  time  it  is  entirely  wrong.  It  is  not  a  mistake 
which  will  immediately  endanger  his  life,  and  he  will  have 
abundant  opportunity  to  correct  himself  in  future  observa- 
tions and  in  the  discussions  which  follow,  and  thus  his 
own  blunders  will  tend  to  make  him  more  acute  in  observ- 
ing. In  most  cases  the  pupil's  work  will  have  enough  of 
accuracy  about  it  to  give  him  self-reliance,  and  his  mis- 
takes will  continually  admonish  him  to  be  cautious. 

If  for  any  reason  a  day  is  missed  during  the  week,  let 
the  space  remain  blank.  Do  the  work  at  the  proper  time 
or  not  at  all.  No  one  should  be  permitted  to  copy  any  part 
of  the  work  from  another  under  any  circumstances. 


5°  NATURE   STUDY.  [September 

In  the  column  under  "  Frost  or  Dew  "  write  "  Frost," 
"  Dew,"  or  "  Neither,"  as  the  case  may  be. 

If  the  wind  is  changing  it  maybe  denoted,  for  example, 
thus  :  S — W,  indicating  a  south  \vind  is  becoming  a  west 
wind.  Pupils  may  learn  its  direction  by  watching  the 
drifting  smoke  from  chimneys. 

The  kinds  of  clouds  should  be  named,  and,  with  the 
sufficiently  advanced  pupils,  the  amount  of  cloudiness  ex- 
pressed in  tenths,  indicating  the  area  above  the  horizon 
that  is  covered. 

The  thermometer  should  hang  on  the  north  side  of  the 
building,  free  from  it,  but  somewhat  protected.  Hang 
the  barometer  where  freely  accessible,  and  so  that  the 
upper  end  of  the  column  of  mercury  will  be  on  a  level 
with  the  pupil's  eye  ;  but  it  must  not  be  too  much  exposed. 

Rainfall  may  be  expressed  as  light,  heavy,  or  none,  and 
the  number  of  hours  and  time  when  it  fell  may  be  re- 
corded. Example,  Light,  1:00 — 4:30  p.  M. 

The  records  for  the  remaining  columns  may  be  taken 
from  an  almanac,  inasmuch  as  the  pupils  will  hardly  be 
able  to  gather  the  data  themselves  with  an  accuracy 
sufficient  for  the  purpose  required.  Much  of  the  material 
here  tabulated  will  be  used  under  the  lessons  in  Astron- 
omy, and  it  is  of  great  advantage  to  have  it  so  that  a 
month's  record  may  be  scanned  at  a  glance.  The  pupils 
will  soon  begin  to  find  out  in  these  columns  a  series  of 
causes  whose  effects  appear  in  the  others. 

Represent  the  moon's  phases  by  small  drawings  of  the 
new  moon,  first  quarter,  half  full  moon,  and  last  quarter, 
making  the  horns  of  the  waxing  moon  to  the  left  and  of 
the  waning  moon  to  the  right.  The  new  moon  may  be 
represented  by  an  open  circle,  and  full  moon  by  one  that 
is  shaded. 


September]  METEOROLOGY.  51 

Both  weekly  and  monthly  summaries  should  be  made 
out  at  the  proper  time.  The  character  and  fullness  of 
these  will  depend  upon  the  age  of  the  pupils,  but  may  in- 
clude the  following  points  :  (i)  Number  of  dews  or  frosts, 
indicated  thus  :  3  D.  2  F.  2  N.;  (2)  prevailing  wind  ;  (3) 
number  of  cloudy  days,  and  number  of  clear  days  ;  (4) 
number  of  days  on  which  rain  fell  ;  (5)  mean  tempera- 
ture ;  (6)  mean  barometer ;  (7)  length  of  day  ;  (8) 
total  increase  or  decrease  in  day's  length  ;  (9)  total 
variation  in  time  of  rising  or  setting  of  moon. 

In  the  consideration  of  the  questions  and  suggestions 
which  follow  there  should  be  a  constant  search  for  the 
causes  underlying  the  phenomena  observed.  It  is  not  ex- 
pected that  each  set  of  questions  will  be  "  finished  "  be- 
fore taking  the  next.  Many  of  the  questions  are  of  such 
character  as  to  require  the  data  which  may  be  collected 
during  several  months'  observation  before  they  can  be  sat- 
isfactorily answered.  The  teacher  must  carefully  note  the 
ability  of  the  pupils  to  think,  and  thus  determine  to  what 
extent  the  questions  should  be  pursued,  being  careful  to 
go  no  farther  than  the  pupils'  knowledge  of  geography 
and  physics  will  warrant.  The  aim  is  twofold — to  make 
him  intelligent  respecting  the  forces  about  him,  and  to 
train  him  in  the  habit  of  studying  a  subject  for  himself  in 
its  relations  to  other  subjects.  The  teacher  is  too  apt  to 
try  to  push  the  pupil  faster  than  he  should  go  by  simply 
telling  him  facts,  instead  of  patiently  giving  him  intelli- 
gent assistance  in  gathering  them  for  himself. 

If  it  is  desired  to  measure  the  amount  of  rainfall,  a  rain 
gauge  can  be  made  by  a  tinsmith  at  small  cost.  For  de- 
scription and  drawing  of  one,  as  well  as  for  valuable  hints 
regarding  meteorological  observations,  see  "  Instructions 
to  Voluntary  Observers  of  the  Signal  Service,"  a  pamphlet 


5 2  NATURE   STUDY.  [September 

which  may  be  obtained  free  by  sending  to  the  Chief  of 
Weather  Bureau,  Washington,  D.  C.  Daily  Weather 
Bureau  maps  may  be  obtained,  also,  by  applying  to  the 
officer  in  charge  of  the  nearest  station.  They  will  be 
found  to  be  interesting  and  useful  in  making  compari- 
sons, and  in  enabling  one  to  trace  the  great  storms  across 
the  country. 

Most  of  the  following  questions  may  be  used  in  study- 
ing both  the  weekly  and  monthly  summaries. 

The  following  charts  show  how  the  pupils  may  be 
taught  to  represent  graphically  many  of  the  summaries 
which  they  should  be  required  to  make  of  their  meteor- 
ological and  astronomical  observations.  In  each  chart, 
part,  or  in  some  cases  the  entire  record  for  the  year  from 
September,  1890,  to  September,  1891,13  represented  for  the 
purpose  of  illustrating  their  use. 

In  Chart  I  the  record  begins  September  25,  the  date 
when  the  day  and  night  are  equal.  At  that  time  the  slant 
of  the  sun's  rays  at  noon  at  Chicago  as  found  by  the 
shadow-stick  is  43°.  At  the  equator  the  slant  is  o° 
which  is  shown  to  the  left  of  the  chart.  At  about  the 
same  time  in  October  the  slant  is  found  to  be  54°,  or 
11°  more  than  in  September.  Since  each  space  between 
the  horizontal  lines  represents  4°,  by  measuring  down 
the  October  line  the  point  for  54°  is  readily  found. 
These  two  points  are  now  connected  by  a  straight 
line,  and  the  work  is  thus  continued  from  month  to 
month. 

In  Chart  II,  it  will  be  seen  that  while  in  Chart  I  the 
line  moved  downward  indicating  the  increasing  slant  of 
the  sun's  rays,  here  the  line  moves  upward,  showing  a  cor- 
responding decrease  in  the  length  of  day.  The  down- 
ward line  representing  in  the  left  hand  side  the  increasing 


September]  METEOROLOGY.  53 

length  of  night  in  the  same  time.  Chart  I  indicates  a 
cause  and  Chart  II  represents  a  very  closely  corresponding 
effect  in  the  length  of  day  and  night.  It  will  be  noticed 
that  the  figure  representing  the  short  days  and  long  nights, 
(the  one  on  the  left)  is  smaller  than  the  one  representing 
the  long  days  and  short  nights,  Also  that  the  longest  day 
is  15  hrs.  5  min.  long  while  the  longest  night  is  but  14 
hrs.  45  min.  long  ;  that  the  shortest  day  is  9  hrs.  15  min. 
and  the  shortest  night  8  hrs,  55  min.  long.  Also,  that 
from  September  25  to  March  17  there  are  but  173  days  ; 
while  from  March  17  to  September  25  there  are  192 
days.  These  are  only  a  few  of  the  many  problems 
which  a  comparison  of  the  charts  will  suggest. 

In  Chart  III  each  horizontal  space  represents  one- 
tenth  of  an  inch,  and  the  column  of  figures  to  the  left 
enables  the  pupils  to  readily  find  the  points  on  the  verti- 
cal lines  which  represent  the  mean  height  of  the  baro- 
metric column.  The  reduction  to  sea  level  need  not  be 
made  by  the  pupils,  but  tables  and  formulae  showing  how 
it  is  done  are  given  in  "Instructions to  Voluntary  Observ- 
ers of  the  Signal  Service." 

In  Chart  IV  the  column  of  figures  to  the  left  represents 
degrees  of  temperature.  By  means  of  these,  the  point 
which  will  represent  the  mean  temperature  for  each  month 
on  the  vertical  line  will  be  easily  found.  Why  is  it  that 
the  line  on  this  chart  corresponds  less  closely  to  that 
on  Chart  I  ? 

Chart  V  needs  no  explanation,  the  name  of  the  month 
being  written  at  the  end  of  the  arrow  which  indicates  the 
direction  of  its  prevailing  wind. 

Chart  VI  shows  at  a  glance  the  total  rainfall  for  each 
month  and  for  the  year,  each  horizontal  space  represent- 
ing one-half  an  inch. 


54  NATURE   STUDY.  [September 

Chart  VII  shows  the  number  of  rainy  days  in  each 
month  and  for  the  year.  This  chart  was  prepared  from 
the  Weather  Bureau  Reports,  in  which  not  less  than  one- 
hundreth  of  an  inch  is  considered.  The  pupils  may  easily 
make  the  record  without  any  measurements,  merely  keep- 
ing count  of  the  days  on  which  rain  falls. 

As  these  charts  are  being  made  from  month  to  month 
they  should  be  constantly  compared  with  each  other  for 
the  purpose  of  tracing  points  of  correspondence  and  dif- 
ference. Lead  the  pupils  to  find  out  which  of  the  charts 
represent  causes  and  which  represent  effects  of  those 
causes,  and  which  ones,  if  any,  appear  to  be  independent 
of  the  others.  Compare  the  three  representing  the  mean 
barometer,  rainfall,  and  direction  of  wind.  Note  the  ex- 
tremes shown  during  each  season  and  for  the  entire  year. 
The  study  may  be  pursued  with  almost  endless  variation 
and  will  be  found  useful  in  working  out  the  problems 
and  suggestions  given  in  the  Outlines  under  the  heads 
of  Meteorology  and  Astronomy.* 

1.  What  wind  was  accompanied  by  the  lowest  temper- 
ature?    The  highest  temperature?     Can  you  give  a  good 
reason  for  this  ? 

2.  Is  the  temperature  increasing  or  diminishing  ? 

3.  Did  the   prevailing   wind  accompany   a  cloudy    or 
a  clear  sky  ? 

*  These  charts  are  prepared  in  book  form  by  the  author,  of  suitable 
size  for  school  use,  in  the  SCIENCE  RECORD  for  the  common  schools. 
This  record  also  contains  twelve  pages  of  blank  Meteorological  Rec- 
ords, one  for  each  month,  twelve  pages  of  blank  records  for  minerals, 
with  a  synoptical  key  to  the  terms  used  in  description,  twelve  pages 
for  notes  on  the  regular  science  work  for  the  year,  twelve  pages  for 
notes  on  miscellaneous  observations,  and  twelve  pages  of  drawing 
paper  for  drawings  and  paintings.  The  size  of  the  page  is  8^xii 
inches. 


September]  METEOROLOGY.  55 

4.  What    direction    was   the   wind    on   cloudy    days  ? 
What  wind  prevailed  on  clear  days  ? 

5.  Was  the   prevailing  wind    accompanied  by  wet  or 
dry  weather  ?     Consult  maps  and  globe  in  looking  for  a 
reason. 

6.  What  was  the  character  of  the  weather  when  the 
barometer  was  lowest  ?     Note  temperature  and  direction 
of  wind. 

7.  What  was  the  weather  like  when  the  barometer  was 
highest  ? 

8.  What  were  the  indications  of  the  thermometer  and 
barometer  when  the  heaviest  rain  fell  ? 

9.  What  change  followed  with  clearing  weather  ? 

10.  Watch  closely  the  indications  of  the  thermometer 
and  barometer,  before,   during,   and  after  rainfall  ;    are 
they  uniform  ? 

11.  At  what  time  of  the  day  is  the  temperature  high- 
est ?    What  reason  can  you  see  for  this  ? 

12.  What  kind  of  weather  has  prevailed  on  the  days 
on    which   there   was    no    dew?     Has   there    been    any 
uniformity   in    the   weather    on   days   when    there   was 
dew? 

13.  What  was  the  character  of  the  nights  when  there 
was  no  dew  ?     When  there  was  dew  ? 

14.  Is  dew  to  be  found  everywhere  and  upon  all  kinds 
of  objects  ? 

STUDY  OF  THE  WEATHER  BUREAU  MAPS. 

Learn  well  the  meaning  of  the  various  lines  and  sym- 
bols used  on  the  map,  and  explained  in  the  margin. 

15.  Note  the  general  direction  of  the  isotherms.     In 
what  region  do  they  vary  most  from  this  direction  ? 

16.  What  effect  do  the  mountain  ranges  have  upon  the 


NATURE    STUDY. 


[September 


lines  ?      The    Great   Lakes  ?      The  coast  lines  ?       The 
river  valleys  and  basins  ? 

17.  Note  the  regions  marked    "Low"   and  "High." 
Which  marks  a  storm  center  ?     Where  have  most  of  these 
entered  the  United  States  during  September  ? 

18.  How   does   the   wind   blow  about   these  centers  ? 
Can  you  discover  any  uniformity  in  this  regard  ? 

19.  What  has  been  the  direction  of  storm  movement 
during  September  ? 

20.  Has  the   movement    been    visibly    influenced   by 
mountains,  river  valleys,  or  coast  lines  ? 

BOOKS  FOR  REFERENCE.     Light  Science  for  Leisure  Hours.    Hum 
boldt  Library,  No.  i,  chapter  on  Tornadoes. 


Sept.Oct.Nov.Dec.Jan.Feb.Mch.Apr.MayJuneJ'yAug.Sept. 
'28°2-TRr^—  — *-    ' ' ' ' • 


24° 

20° 
16° 
12° 
8° 
4° 
6° 
4° 
8° 
1-2° 
16° 
20° 
24° 


54 


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CHART  I. — Showing  variation  in  the  slant  of  the  sun's  rays  at  Chi- 
cago from  September  to  March  inclusive.  Record  taken  from  the 
shadow-stick  of  the  eighth  grade,  Cook  County  Normal  Practice 
School.  (Not  absolutely  correct.) 


September] 


METEOROLOGY. 


57 


Sept.  Oct.  Nov.  Dec.'Jan.  Feb.Mch.Apr.May  June  July  Aug.  Sepfa 


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CHART  I II. — Showing  mean  height  of  barometric  column  at  Chi- 
cago for  each  month  from  September  to  May  inclusive,  1890-91. 
(Reduced  to  sea  level.) 


5&  NATURE   STUDY.  [September 

,  Sept.    Oct.     Kov.    Dt.f.     Jan.     Feh.   March   Apr.    May     Jime    July    Ang.    Sept. 


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CHART    IV. — Line  showing  mean  temperature  of  each  month  at 
Chicago  from  September  to  May  inclusive,  1890-91. 

October 


NORTH 


September 


November 
December 
January 
February 


SO 


May 
April 
March 


EAST 


TH 


CHART  V. — Showing  prevailing  winds  at  Chicago  for  each  month 
from  September  to  May  inclusive,  1890-91. 


September] 


METEOROLOGY. 


59 


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CHART  VI.  —Showing  rainfall  at  Chicago  for  each  month  from  Sep- 
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CHART  VII. — Showing  the  number  of  days  on  which  at  least  .01 
inch  of  rain  fell  at  Chicago  in  each  month  from  September  to  May  in- 
clusive, 1890-91. 


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1  WEEKLY 

SUMMARY 

astronomy 


GENERAL  DIRECTIONS. 

In  following  up  these  observations  with  explanations, 
it  is  necessary  to  be  provided  with  a  globe,  or  a  good 
substitute,  and  objects  to  represent  the  sun,  moon,  and 
planets. 

If  an  open  space  on  the  floor,  a  few  feet  square,  is  avail- 
able, a  spot  in  the  middle  should  be  selected  to  represent 
the  position  of  the  sun,  and  ellipses  drawn  around  it  with 
light  lines  of  paint  to  represent  the  orbits  of  the  planets. 

The  surface  of  a  large  table  may  be  used  if  floor  room 
cannot  be  obtained.  Representing  the  distance  of  the 
earth  from  the  sun  by  i,  the  distance  of  the  planets  may 
be  approximately  represented  as  follows  :  Mercury  I  ; 
Venus  | ;  Earth  i  ;  Mars  | ;  Jupiter  5  ;  Saturn  9  ;  Uranus 
20  ;  Neptune  30.  For  the  purposes  of  illustration  in  the 
following  lessons  it  will  be  more  convenient  to  represent 
the  earth's  distance  on  a  larger  scale  than  that  on  which 
it  would  be  practicable  to  represent  the  whole  solar  sys- 
tem. The  varying  length  of  shadow  should  be  observed 
throughout  the  year.  To  do  this,  take  a  strip  of  wood 
two  feet  long  and  two  inches  in  width,  and  to  one  end 
nail  an  upright  strip  of  same  width  and  four  inches 
high.  At  noon  place  the  long  strip  in  a  horizontal  posi- 
tion on  a  north  and  south  line  with  the  upright  toward 
the  south.  With  a  pencil  and  ruler  draw  a  line  across 
the  horizontal  strip  marking  the  limit  of  the  shadow  cast 


62  NATURE  STUDY.  [September 

by  the  upright.  Note  the  date  each  time.  The  angle 
made  by  the  sun's  rays  may  be  found  thus  :  Take  a  stiff 
piece  of  cardboard  six  inches  square,  describe  upon  it  a 
semicircle,  and  if  a  protractor  be  at  hand,  lay  off  the 
semi-circumference  in  degrees.  Tack  or  paste  this  to  a 
piece  of  wood  of  same  size  as  the  cardboard  and  one- 
half  inch  thick  ;  along  the  edge  of  this,  which  is  opposite 
to  the  diameter  of  the  semicircle  and  parallel  with  it, 
tack  a  straight  strip  of  wood  half  an  inch  square  and  one 
foot  long.  Cut  from  a  piece  of  tin  or  thin  brass  a  pointer 
three  inches  long,  and  swing  it  on  an  axis  or  pivot  fast- 
ened at  the  center  of  the  circle.  The  pointer  will  always 
hang  down  when  the  dial  is  upright.  To  number  the 
degrees  on  the  dial,  place  it  so  that  the  stick  which  is 
fastened  to  the  base  will  be  horizontal,  with  the  dial 
uppermost.  The  pointer  will  then  be  vertical,  and  zero 
degrees  may  be  marked  at  this  point.  As  either  end 
of  the  stick  is  raised  the  pointer  will  still  remain  verti- 
cal, and  indicate  the  number  of  degrees  it  is  raised 
from  the  horizontal.  To  get  the  angle  of  the  sun's  rays, 
place  one  end  of  the  stick  at  the  extreme  edge  of  the 
shadow  and  allow  the  other  to  rest  on  the  top  of  the 
upright  which  casts  it.  The  pointer  will  give  the  num- 
ber of  degrees  the  sun  is  above  the  horizon. 

The  most  important  conception  for  the  children  to  get 
in  this  study  is  that  of  time,  and  a  conception  of  space  is 
next.  When  necessary,  daily  practice  should  be  given 
the  children  in  telling  the  exact  time  of  day  by  clock  or 
watch,  until  they  can  do  so  without  hesitation.  Of  course, 
merely  telling  the  time  of  day  will  not  in  itself  give  a  con- 
ception of  time,  and  such  exercises  as  will  enable  them  to 
grasp  brief  periods  must  be  given  in  connection  with  it. 
As  for  example,  let  them  find  out  how  long  it  takes  them 


September]  A  S  TRONOM  Y.  63 

to  walk  home  ;  or,  the  length  of  the  recitation  period,  or 
of  the  morning  and  afternoon  sessions  of  school,  the 
recess  and  noon  periods,  etc.,  and  they  will  soon  fix  in 
their  minds  a  stock  of  time  units  which  will  be  of  great 
service. 

1.  What  do  you  notice  about  the  relative  length  of  day 
and  night  at  the  beginning  of  the  month  ? 

2.  With  a  globe  and  some  object  to  represent  the  sun, 
find  out  the  relative  positions  of  the  two  bodies  when  day 
and  night  are  thus  related  in  length. 

3.  How  does  the  length  of  each  vary  during  the  month  ? 

4.  Using  the  globe  as  before,  explain  this  change. 

5.  How  has  the  length  of  the  noon  shadow  changed  ? 
By  using  the  globe  explain  this. 

6.  Observe  as  accurately  as  possible  the  two  points  on 
the  horizon  where  the  sun  rises  and  sets  on  that  date  in  this 
month  when  day  and  night  are  equal.     Fix  these  points 
with  respect  to  yourself  by  means  of  a  tree,  post,  or  some 
permanent  mark,  and  keep  in  mind  for  reference  in  future 
observations.     A  line  connecting  these  two  points  runs 
east  and  west.     Compare  the  length  of  day  and  night. 
This  date  is  the  time  of  the  Autumnal  Equinox. 

7.  Make  a  brief  note  of  the  condition  of  animal  and 
plant  life  at  this  time  and  preserve  for  future  reference. 

Among  the  interesting  constellations  that  may  be  ob- 
served during  this  month  are  :  Great  Bear,  Little  Bear, 
Draco,  Cassiopeia,  Cepheus,  Pegasus,  Sagittarius,  Lyra> 
Cygnus,  Dolphin,  Hercules,  Corona,  Berenice's  Hair. 

BOOKS  FOR  REFERENCE.  Science  Primer,  Astronomy,  Lockyer. 
The  Wonders  of  the  Heavens,  Humboldt  Library,  No.  14. 


Geography  is  defined  as  a  description  of  the  earth. 
This  embraces  everything  that  may  be  said  of  the  earth, 
but  it  is  usually  understood  to  have  a  more  limited  mean- 
ing. It  is  sometimes  said  to  be  a  study  of  the  earth  as  a 
finished  product ;  that  cannot  be  strictly  true,  for  it  is  no 
more  a  finished  product  to-day,  in  the  sense  that  it  is  in  a 
fixed  condition,  than  it  ever  was.  It  has  been  constantly 
changing  from  the  remotest  periods  of  time  under  the 
operation  of  certain  laws,  and  those  laws  are  still  affect- 
ing it.  The  changes  in  the  earth  itself,  and  in  its  relations 
to  the  other  portions  of  the  universe,  have  produced  cor- 
responding modifications  in  living  things  ever  since  mun- 
dane life  began  to  exist.  They  are  so  gradual  as  to  have 
had  but  the  most  trifling  import  in  the  time  spanned  by 
human  history,  yet  it  is  believed  that  by  them  the  earth 
has  been  brought  out  of  a  nebulous  condition  to  its  present 
state.  Life,  both  animal  and  plant,  by  its  amazing  plas- 
ticity adapting  itself  to  almost  every  corner  of  the  globe, 
has  managed  to  survive  and  perpetuate  itself  throughout 
countless  ages  of  a  vast  period,  in  which  the  changes  have 
been  almost  incredible. 

Geography,  as  it  is  to  be  understood  here,  is  the  study 
of  the  earth  in  its  present  condition  as  a  cause,  of  which 
life  upon  it  is  the  effect.  It  comprehends  a  study  of  the 
earth  in  its  present  relation  to  life,  and  a  study  of  life,  as 
it  now  exists  in  its  adaptation  to  the  earth. 

64 


September]  GEOGRAPHY.  65 

DIRECTION. 

Teach  the  cardinal  points  and  apply  in  giving  Jthe 
direction  of  the  wind,  movement  of  clouds,  etc.  (see 
Meteorology),  and  in  the  location  of  articles  in  the  room, 
school-yard,  and  vicinity. 

Countless  problems  may  be  proposed  by  both  teacher 
and  pupils  which  will  give  zest  to  the  work  and  cultivate 
a  habit  in  the  children  of  keeping  their  bearings  when 
moving  about  from  place  to  place.  The  unpleasant  ex- 
perience which  most  people  have  had  of  being  "  turned 
round,"  when  in  a  strange  place,  as  to  the  points  of  the 
compass,  is  probably  due  chiefly  to  the  fact  that  they  do 
not  habitually  observe  fixed  landmarks  with  respect  to 
the  cardinal  points  on  the  horizon  while  traveling.  The 
pupils  should  be  practiced  in  this  until  it  becomes  a  fixed 
habit,  and  they  are  able  to  hold  the  different  directions 
in  mind  without  conscious  effort. 

With  this  work,  map  making  properly  begins.  If  one 
pupil  says  that  in  going  home  he  travels  three  blocks  east 
and  two  north,  let  him  show  how  the  path  looks  on  the 
blackboard.  Let  him  locate  his  home  and  the  school- 
house  with  respect  to  each  other.  This  will  necessitate 
the  teaching  of  direction  as  applied  to  maps. 

LATITUDE  AND  LONGITUDE. 

In  beginning  with  pupils  to  use  latitude  and  longitude 
in  the  location  of  places,  if  it  can  be  avoided,  never  use  a 
flat  map.  A  globe  is  the  only  thing  that  can  give  a  cor- 
rect idea  of  the  parallels  and  meridians  as  they  are  re- 
lated to  each  other. 

i.  Locate  the  equator  and  the  poles  on  the  globe. 
What  is  the  position  of  the  equator  between  the  poles  ? 


66  NATURE   STUDY.  [September 

2.  How  far  from  the  equator  to  the  poles  ?  Teach  the 
number  of  degrees  in  a  circle,  half  circle,  and  quadrant. 

J.  When  the  rays  of  the  sun  just  reach  either  pole, 
where  are  the  vertical  rays  ?  On  what  date  is  this  the  case  ? 

4.  What  do  you  notice  about  the  length  of  day  and 
night  at  this  time  ? 

5.  When  the  sun  is  vertical  at  the  equator,  what  is  the 
angle  of  the  rays  in  our  latitude  at  noon  ?     (See  Astron- 
omy for  September.) 

6.  What  determines  the  size  of  the  angle  at  this  time  ? 

7.  How  would  the  angle  change  if  we  moved  north  ? 
If  we  moved  south  ?     If  we  moved  east  or  west  ? 

8.  If  you  know  the  angle  of  the  sun's  rays  at  noon  at 
a  given  place  when  the  sun  is  vertical  at  the  equator,  how 
can  you  find  the  latitude  of  that  place  ? 

9.  In  what  latitude  have  the  severest  storms  originated 
in  the  United  States    this  month  ?    (See  Weather  Bureau 
Map  Studies  for  September.) 

10.  How  many  degrees  of  longitude  has  the  heaviest 
storm  passed  over  ? 

11.  In  what  latitude  have  the  heaviest  rains  fallen  ? 

12.  What  latitude  has  been  least  visited  by  storms  ? 

13.  In  what  latitude  do  the  isotherms  vary  most  widely 
from  their  general  course  ?     In  what  latitude  do  they  vary 
least  ? 

14.  Since  the  earth  rotates  once  in  twenty-four  hours, 
through  how  many  degrees  does  each  point  on  the  earth's 
surface  pass  in  that  time  ?• 

15.  Upon  what  circles  are  the  degrees  measured  ?   Are 
the  degrees  of  the  same  size  on  different  circles  ? 

16.  Through  how  many  degrees  will   any  given  point 
pass  in  one  hour  of  time  ?     On  what  circle  would  a  point 
pass  through  the  greatest  number  of  miles  ? 


September]  GEOGRAPHY.  67 

Longitude  is  reckoned  east  and  west  from  an  estab- 
lished meridian,  usually  that  passing  through  Greenwich, 
near  London,  or  the  meridian  passing  through  Washing- 
ton. 

17.  How  many  degrees  of  east  or  west  longitude  can 
be  reckoned  ?  Where  will  there  be  no  longitude  ?  Where 

no  latitude  ? 

NORTH  AMERICA. 

1.  Between   what  parallels  does  North   America   lie? 
Between  what  meridians  ? 

2.  What  contrasts  between  the  northern  and  southern 
parts,  due  to  difference  in  latitude,  are  found  in  animal 
life,  vegetation,  habits,  character,  and  occupations  of  the 
people  ? 

3.  What  are  some  of  the  advantages  of  a  country  that 
extends  through  many  degrees^of  latitude  ? 

4.  What  are  the  greatest  disadvantages  due  to  the  same 
conditions  ? 

5.  How  did  difference  of  latitude,  as  a  cause,  enter 
into  the  questions  involved  in  the  great  civil  war  in  the 
United  States  ? 

6.  When  it  is  sunrise  at  New  York  City,  how  long  be- 
fore sunrise  at  San  Francisco  ? 

7.  When  it  is  sunset  at  St.  Louis,  how  long  after  sunset 
at  Washington  ? 

To  make  the  pupils  familiar  with  maps  and  their  use, 
they  should  begin  by  modeling  and  drawing  maps  of  the 
school-room,  school  grounds,  and  surroundings.  Mark 
the  natural  features  of  surface,  and  locate  the  buildings, 
etc.,  that  are  to  be  found  upon  it.  Locate  on  map  and 
globe  alt  places  mentioned  in  history  and  other  subjects 
studied.  This  should  be  as  much  a  matter  of  habit  as  it 
is  to  look  for  the  meaning  of  a  word  in  a  dictionary. 


The  conception  of  space  is  of  first  importance  in  this 
study,  and  that  of  time  is  second.  Means  should  be  pro- 
vided in  the  beginning  to  enable  the  pupil  to  train  himself 
accurately  in  judging  distances,  horizontal  and  vertical, 
and  areas.  The  deficiency  of  pupils,  even  of  high  school 
age,  in  this  respect  is  generally  very  great.  This  is  almost 
wholly  due  to  lack  of  actual  practice  ;  they  have  talked  a 
great  deal  about  rods  and  acres,  but  have  never  measured 
them. 

The  units  must  be  adapted  to  the  age  and  comprehen- 
sion of  the  children,  but,  as  needed,  one-fourth,  one-half, 
and,  if  possible,  one  mile  should  be  laid  off,  so  that  the 
limits  may  be  plainly  seen  and  the  distances  well  fixed  in 
mind.  There  should  be  similar  opportunities  given  to 
study  one  foot,  one  yard,  one  rod,  and  one  hundred  yards. 
For  the  study  of  heights,  units  of  ten,  twenty-five,  and,  if 
possible,  fifty  and  one  hundred  feet  should  be  marked  off 
on  the  side  of  the  school-house  or  some  tree.  The  square 
foot,  square  yard,  square  rod,  acre,  and  later  the  square 
mile,  will  be  needed  in  the  estimation  of  areas. 

It  is  well  to  give  much  attention  from  the  start  to  the 
collection  of  specimens.  Every  region  will  furnish  an 
abundance  of  many  different  kinds,  and  they  possess  an 
immense  advantage  over  collections  in  some  other 
branches  of  natural  history,  from  the  fact  that  they  re- 
quire little  care,  except  an  occasional  dusting,  and  are 
practically  imperishable.  Fragments  of  different  rocks, 

68 


September]  GEOLOGY.  69 

various  kinds  and  forms  of  pebbles,  and  fossils  of  all 
kinds,  should,  when  possible,  be  gathered  and  neatly  ar- 
ranged. There  can  hardly  be  a  stronger  stimulus  for  the 
imagination  than  that  which  one  receives  from  the  proper 
study  of  a  fossil,  and  there  is  certainly  nothing  which 
will  so  broaden  one's  conceptions  regarding  the  vast  ages 
that  make  up  the  earth's  history.  Arrange  in  a  tray  or 
box  certain  typical  specimens  of  those  belonging  to  the 
immediate  neighborhood,  with  which  the  pupils  may  com- 
pare their  specimens  as  they  find  them.  Among  these 
may  be  granite,  marble,  limestone,  sandstone,  slate,  coal, 
etc.  The  name  should  not  be  given  to  them  by  the 
teacher  until  they  have  compared  their  specimen  with  the 
types  and  learned  some  of  its  characters.  None  the  less, 
however,  should  the  pupils  be  led  to  study  the  dynamical 
side  of  the  subject.  There  are  everywhere  plenty  of  ex- 
cellent examples  of  either  building  or  wearing  away, — per- 
haps both, — which  possess  an  abiding  interest.  Whatever 
it  may  be,  whether  a  crumbling  cliff,  a  building  beach,  a 
deepening  gulch,  or  a  slowly  filling  marsh,  it  makes  but 
little  difference.  There  to-day  the  Titans  may  be  seen 
making  and  unmaking  the  world,  as  they  have  been  doing 
it  for  unnumbered  ages  in  the  past. 

1.  In  looking  over  the  country  about  you,  can  you  tell 
what  has  been  the  most  important  agent  in  its  formation  ? 

2.  Is   the   same  force  still   at   work  ?     Is   it  working 
rapidly  or  slowly  ? 

3.  What  other  forces  have  left  their  impress  upon  the 
country  ?     Are  they  still  acting  ? 

4.  Are  there  any  evidences  as  to  whether  these  forces 
ever   worked   more    rapidly   or   more    powerfully   than 
now  ? 

5.  Can  you  find  any  place  where  the  land  is  being  torn 


7°  NATURE   STUDY.  [September 

down  ?     What  is  doing  it  ?     What  becomes  of  the  ma- 
terial when  torn  away  ? 

6.  Are   there   any    forces   which   oppose   the   tearing 
away? 

7.  Are  there  any  marshes,  large  or  small,  in  the  vicin- 
ity ?     How  much  of  their  history  can  you  read  in  them  ? 

8.  What  was  their  relation  originally  to  the  nearest  lake 
or  stream  ? 

9.  Are  they  now  rilling  up  with  earth,  or  being  hollowed 
out  ? 

10.  What   is   vegetation   doing   for  the  marsh  ?     The 
water  ? 

11.  How  does  a  sod  affect  the  wearing  forces  of  any 
region  ?     What  are  the  effects  of  forests  ? 

12.  Is  the  cultivation  of  the  soil  in  anyway  changing 
the  formation  of  the  country  ? 

13.  What  kind  of  rock  underlies  the  surface  ?     Do  you 
find  more  than  one  kind  ? 

14.  Are  they  in  layers,  /.  e.,  stratified,  or  in  masses  that 
show  no  stratification  ? 

15.  If  stratified,  are  the  strata  horizontal  or  inclined  ? 
When  inclined  the  rock  is  said  to  dip.     The  line  along 
which  the  edge  of  the  rock  cuts  the  surface  is  called  the 
strike.     It  always  runs  at  right  angles  with  the  dip. 

1 6.  What  is  the  angle  of  dip  measured  from  the  hori- 
zontal ? 

1 7.  Does  the  dip  have  the  same  angle  in  all  places  ? 
Does  it  have  the  same  direction  ? 

BOOKS  FOR  REFERENCE.     Humboldt  Library,  No.  6,  Town  Geol- 
ogy.    Shaler's  First  Book  in  Geology. 


Give  special  attention  to  the  collection  and  arrange- 
ment of  different  metals  and  minerals.  Provide  a  small 
tray  with  compartments,  in  which  there  should  be  placed 
typical  specimens  of  such,  at  least,  as  are  likely  to  be 
found  in  the  vicinity.  Place  with  each  one  a  label  bear- 
ing its  degree  of  hardness,  its  luster,  color,  diaphaneity, 
streak,  taste  or  odor,  and  name.  The  scale  of  hardness 
consists  of  ten  minerals,  showing  a  regular  gradation  in 
hardness  from  talc,  one  of  the  softest,  to  diamond,  one  of 
the  hardest  minerals.  It  is  as  follows  :  Very  soft — i,  talc  ; 
2,  gypsum  ;  can  be  scratched  with  finger-nail,  or  very 
easily  with  a  knife.  Soft — 3,  calcite  ;  4,  fluorite  ;  can- 
not be  scratched  with  the  nail,  but  easily  scratched  with 
a  knife.  Hard — 5,  apatite  ;  6,  orthoclase  ;  not  easily 
scratched  with  a  knife  ;  scratches  glass.  Very  hard— 
7,  quartz  ;  cannot  be  scratched  by  a  knife,  scratches 
glass  ;  8,  topaz,  scratches  quartz.  Adamantine — 9,  cor- 
undum ;  scratched  by  the  diamond  and  itself.  10,  dia- 
mond j  not  scratched  by  any  other  mineral. 

Luster  or  glance  refers  to  the  light,  both  as  to  quality 
and  quantity,  which  is  reflected  from  the  surface.  The 
metallic  luster  is  that  of  the  metals.  All  the  other  kinds 
of  luster  are  embraced  under  the  general  division  non- 
metallic.  The  chief  varieties  are  :  Vitreous,  like  glass  ; 
pearly,  as  in  mica  or  pearl  ;  resinous,  as  in  resins,  sulphur 
and  sphalerite  ;  silky  or  satiny,  as  in  satin-spar ;  greasy  or 
waxy,  as  in  serpentine. 


7 2  NATURE   STUDY.  [September 

The  degrees  of  diaphaneity  are  expressed  as  trans- 
parent^ translucent,  and  opaque.  The  streak  is  obtained 
by  powdering  a  little  of  the  mineral  by  means  of  a  file, 
or  by  drawing  it  over  a  piece  of  ground  glass. 

Use  the  magnet  in  the  examination  of  metals,  and  find 
out  which  are  magnetic  and  which  are  not.  When  a 
mineral  is  found  by  a  pupil  he  should  prepare  a  written 
description  of  it,  including  the  characteristics  above 
given,  by  comparing  it  with  the  specimens  labeled  in  the 
tray.  The  teacher  may  then  add  the  name.  The  col- 
lecting should  be  encouraged  throughout  the  year. 

From  the  beginning  the  pupils  should  be  taught,  in  the 
grammar  grades,  at  least,  the  best  means  by  which  a  com- 
plete but  concise  record  of  their  observations  may  be  kept. 
Although  it-  may  appear  a  little  tedious  at  first,  its  value 
will  be  more  and  more  apparent  as  the  record  grows.  The 
irksomeness  of  the  task  is  usually  chiefly  due  to  the  fact 
that  the  pupil  is  urged  to  record  observations  which  he 
has  not  really  made,  and,  being  no  part  of  his  experi- 
ence, he  naturally  has  no  interest  in  them.  He  should 
record  briefly  only  what  he  can  find  out  for  himself. 
The  blank  form  for  a  mineralogical  record,  here  appended, 
may  be  prepared  upon  the  sheet,  eight  and  one-half 
by  eleven  inches,  which  was  recommended  on  a  previous 
page  for  science  work.  This  will  give  space  enough  for 
ten  minerals,  and  will  be  of  uniform  size  with  the  sheets 
upon  which  his  other  written  work  is  prepared. 

BOOKS  FOR  REFERENCE.  Crosby's  Tables  for  the  Determination 
of  Common  Minerals,  Guttenburg's  Course  in  Mineralogy  for  Young 
People  (Agassiz  Association  Course),  Crosby's  Common  Minerals 
and  Rocks. 


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Suggestions  to  Teachers  for  Using  the  Mineralogical 
Record. 

Each  pupil  should  have  a  blank  record.  When  he  finds  a  mineral,  its  description  is  to 
be  written  in  the  blank  form  under  the  proper  heads  —  the  appended  outline  being 
used  as  a  guide.  Render  the  pupil  as  little  assistance  as  possible  ;  he  must  be  self-reli- 
ant. Do  not  hurry.  When  the  pupil  has  done  his  best,  the  amount  varying  with  age 
and  practice,  the  teacher  may  give  him  the  name  of  the  mineral.  Crosby's  Tables  for 


the  Determination  of  Common  Minerals  is  a  most  valuable  manual  for  teachers. 


I.    SCALH  OF  HARDNESS. 

1.  Talc,         )   VERY  SOFT  ;  can  be  scratched  with  finger  nail,  or  very 

2.  Gypsum, )  knife. 

3.  Calcite,     )   SOFT  ;  cannot  be  scratched  with  finger  nail,  but  easily  scratched 

4.  Fluorite,  )  with  a  knife. 

6!   Orthocfase, }  HABD  :  not  easilv  scratched  with  a  knife  ;  scratches  glass. 

7.  Quartz,)   vwnv  Winr.     $   Cannot  be  scratched  with  a  knife  ;  scratches  glass. 

8.  Topaz,    }   VERY  HARD;  -(    scratches  quartz. 

9.  Corundum,)    AT,iMiVTTvir  • )    Scratched  by  the  diamond  and  itself. 
10.   Diamond,     }  ADAMANTINE  ,  |  Not  gd-atdjed  ^y  any  otner  mineral. 


sily  with  a 


II.    SPECIFIC  GRAVITY. 

1.  Weigh  in  air. 

2.  Weigh  in  water. 

3.  Specific  Gravity  =  weight  in  air  •+•  loss  of  weight  in  water. 

Botryoidal-  Surf  ace  prape-like. 
Mammillary  —  Same,  but  larger. 
Tufaceous—  Porous,  mineral  incrustations  formed  from  solu- 

tions. 

Concretionary—  Rounded  masses. 
Geode—  Hollow  concretion. 

Stalactitic—  Hanging  from  under  surface  of  a  rock,  cone-shaped. 
Stalagmitic—  Formed  on  floors  of  caverns  from  dripping  water. 
Stratified—  Deposited  in  layers. 
Granular,  coarse  or  fine—  Small  crystals. 
Compact  -  Crystals  invisible  to  unaided  eye. 
Foliated—  In  layers. 
Fibrous—  Thread  like. 
Columnar—  Stout,  fibrous. 
Amorphous—  Without  crystallization. 


1.    External. 


2.    Internal. 


IV.    TENACITY. 

1.  Brittle-Breaks  easily. 

2.  Malleable—  Flattens  into  thin  sheets  under  hammer. 

3.  Sectile—  May  be  cut  into  thin  slices. 

4.  Flexible  —  Retains  its  form  when  bent. 

5.  Elastic  -Comes  back  to  original  form  when  bent. 

V.    LUSTER. 

1.  Metallic,  as  in  metals. 

Vitreous,  as  in  glass, 

Pearly,  as  in  pearl  and  mica. 

Resinous,  as  in  sulphur,  sphalerite,  resins. 

2.  Non-Metallic.  Pitchy,  as  in  cannel  coal. 

Silky  or  satiny,  as  in  satin  spar. 
Greasy  or  waxy,  as  in  serpentine. 
^ull,  as  in  chalk. 
VI.    STREAK. 

Color  obtained  by  rubbing  the  mineral  over  the  surface  of  a  piece  of  ground 

glass  or  over  a  file. 
911.    DIAPHANEITY. 

1.  Transparent.   Semi-transparent. 

2.  Translucent.     Sub-translucent. 

3.  Opaque. 

rill.    ACID  TESTS.     Use  H  Cl  (hydrochloric  acid),  or  dilute  Ha  S  CH  (sulphuric  acid), 
or  both.    Use  a  little  of  the  mineral  in  a  test  tube. 

1.  Insoluble. 

(  With  effervescence  ;  with  or  without  heat. 

2.  Soluble.        •<  Without  effervescence  ;  with  or  without  heat. 

(  Gelatinizes—  Becomes  jelly-like. 

IX.  FLAME  TESTS.  N.  B.  Use  a  fine  splinter  of  the  mineral,  or  a  thin  edge  in  the 
flame  of  an  alcohol  lamp  or  bunsen  burner.  Note  the 
color  imparted  to  the  flame. 

1.  Fusible-Melts. 

2.  Infusible  -Does  not  melt. 

3.  Decrepitates—  Breaks  into  small  pieces  with  crackling  sound. 

4.  Intumesces—  Swells  up  without  fusion. 

74 


The  larvae  of  several  different  species  of  moths  (large 
green  and  brown  worms)  are  usually  abundant  at  this 
time,  and  should  be  collected.  Put  them  in  small  boxes 
covered  with  mosquito  netting,  and  feed  with  fresh  leaves 
of  the  plant  upon  which  they  were  found.  They  will  soon 
spin  a  cocoon  and  enter  upon  a  new  stage  of  existence. 
Carefully  preserve  these  through  the  winter,  and  in  the 
spring  the  moth  will  appear.  There  is  not  a  more  fruit- 
ful series  of  observations  possible  in  the  school-room  for 
children  than  that  of  watching  the  wonderful  transforma- 
tion of  insects.  Ants  may  be  kept  under  observation 
during  the  entire  year  in  glass  jars  filled  with  fine  damp 
earth.  A  better  method,  however,  is  as  follows  :  Get  a 
tinsmith  to  fasten  a  small  moat,  an  inch  deep  and  one 
and  a  half  inches  wide,  around  a  smooth  piece  of  inch 
board,  one  foot  square.  On  this  board,  equidistant  from 
the  moat  on  all  sides,  lay  a  pane  of  glass,  ten  inches 
square.  On  each  edge  of  this,  glue  a  strip  of  glass,  leav- 
ing small  passage  ways  at  opposite  corners.  Fill  the 
shallow  vessel  thus  formed  with  finely  sifted  earth,  and 
cover  it  with  another  pane  of  glass  of  same  size  as  the 
lower  one.  Fill  the  moat  with  water.  Take  from  an 
ant-hill  a  small  box  of  earth  and  ants  all  together,  and 
place  them  in  a  little  heap  on  the  top  of  the  glass.  By 
thrusting  a  small  stick  into  the  den  through  the  passage- 
ways left  at  the  corners,  to  give  them  a  place  for  a  beginning, 
with  a  little  care  the  ants  can  be  induced  to  enter  and  go 

75 


76  NATURE   STUDY.  [October 

to  work.  Gradually  remove  the  earth  from  the  top  of 
the  glass,  wipe  clean  and  keep  in  the  dark  by  covering 
the  whole  with  a  pasteboard  lid,  about  two  inches  high. 
Food — crumbs,  sugar,  and  bits  of  meat — can  be  placed 
under  this  on  the  glass.  The  changes  made  from  day  to 
day  in  the  earth,  and  the  management  of  the  larvae, 
visible  through  the  glass,  are  sources  of  unfailing  interest. 
If  a  common  mud  or  snapping  turtle  can  be  procured, 
place  it  in  a  box  of  wet  sand  with  a  loose  lid  over  it,  and 
in  a  few  weeks  it  will  disappear  and  remain  out  of  sight 
till  spring,  and  furnish  a  text  for  the  interesting  subject 
of  hibernation. 

1.  What  birds  have  disappeared  within  the  past  few 
weeks  ?     Note  the  date  when  last  seen, 

2.  Can  you  tell  which  leave  first,  the  old  ones  or  young 
ones? 

3.  Watch  for  migrating  flocks  of  geese  from  the  north. 

4.  What  becomes  of  the  insects  during  the  cold  nights  ? 
Do  any  of  them  migrate  ? 

5.  What  becomes  of  the   butterflies  ?     Of  the   bees  ? 
Of  the  grasshoppers  ?     Of  the  flies  ? 

6.  Can  you  find  any  preparing  to  live  over  winter  ? 

7.  Examine  the  burrows  of  earthworms  ;    are  the  worms 
as  active  as  they  were  last  month  ? 

8.  Gather  a  number  of  snails  from  the  bottoms  of  ponds 
and  preserve  in  glass  jars. 

A  STUDY  OF  TISSUES. 

It  is  of  fundamental  importance  that  pupils  should  have 
in  the  outset  of  the  study  of  physiology  correct  concep- 
tions as  to  the  more  important  tissues  of  the  animal  body. 
The  following  outline  is  intended  to  be  used  as  a  guide  in 
making  them  acquainted  with  these  tissues,  and  to  give 


October]  ZOOLOGY.  77 

an  idea  of  their  uses.  Procure  a  sheep's  leg  cut  off  so  as 
to  include  what  is  commonly  called  the  knee  joint  and 
the  attached  muscles  a  few  inches  above  it.  Each  pupil 
should  have  a  specimen  which  must  be  perfectly  fresh 
and  clean.  The  distaste  that  many  pupils  acquire  for 
this  kind  of  work,  in  the  majority  of  cases,  arises  from 
carelessness  of  the  teacher  on  this  point.  The  use  of 
good  specimens  gives  the  teacher  a  perfect  right  to  require 
each  pupil  to  do  the  work,  and,  feeling  this,  but  few  will 
raise  any  objection. 

THE  MUSCLE. 

1.  Note  the  reddish  flesh  forming  the  body  of  the  muscle. 

2.  The  slender  cord  attaching  the  body  to  the  bone  is 
the  tendon  of  the  muscle.     Is  it  elastic  or  inelastic  ?     Can 
it  be  pulled  loose  ?     Try  pulling  in  different  directions. 

3.  Note  how  it  is  attached  to  the  bone.     The  point  of 
attachment  of  the  tendon  which  moves  least  in  any  mo- 
tion of  the  part  is  called  the  origin  of  the  muscle  ;  the 
other  attachment  is  its  insertion.     Locate  the  origin  and 
insertion  of  the  muscle  which  flexes  the  forearm. 

4.  Note  the  thin  sheath  covering  the  body  ;  it  is  called 
the  perimysium. 

5.  Cut  the  body  crosswise  and  note  the  parts  which 
compose  it.     They  are  best  seen  in  boiled  meat.     The 
bundles  thus  shown  are  called  fasciculi. 

6.  Follow  out  toward  the  tendons  the  white  threads, 
and  note  the  formation  of  the  tendon. 

7.  Find  tendons  in  your  own  body  ;  find  the  bodies  of 
the  muscles  to  which  they  are  attached. 

8.  What  advantage  in  the  tendon  ? 

9.  What  is  the  advantage  of  its  inelasticity  ? 

10.  What  uses  can  you  discover  for  muscle  ? 


7^  NATURE  STUDY.  [October1 

CONNECTIVE  TISSUE. 

1.  Examine   the   white,    thin    tissue    surrounding   the 
muscle. 

2.  What  are  its  characteristics  ?     Is  it  elastic  ?     This 
tissue  is  very  abundant  in  the  specimen,  as  well  as  in  the 
whole  body.     It  is  called  connective  tissue.     It  is  to  be 
found  almost  everywhere,  binding  the  different  parts  to- 
gether.    What  characteristics  especially  adapt  it  to  this 
end? 

3.  In  how  many  forms  does  it  appear  in  this  specimen  ? 
Note  the  tendons,  the  periwysium,  and  the  threads  which 
ramify  the  muscle  body. 

THE  BONE.     OSSEOUS  TISSUE. 

1.  Note  the  slender  shaft  and  its  enlarged  extremities. 

2.  What   advantage    in   the    enlargement   of  the   ex- 
tremities ? 

3.  Look  for  the  sheath  closely  surrounding  the  shaft. 
What  kind  of  tissue  is  it  ?     The  sheath  is  called  the  peri- 
osteum. 

4.  Look  for  the  cavity  in  the  shaft  called  the  medullary 
cavity.     Note  the  contents,  called  the  marrow. 

5.  Split  the  bone  ;  note  the  difference  in  the  character 
of  the  bone  at  the  extremities  and  in  the  shaft. 

6.  In  the  extremities  it  is  called  spongy  or  cancellated  ; 
in  the  shaft,  compact  bone. 

7.  Note  the  red  marrow  in  the  spongy  bone. 

8.  What  advantage  is  gained  by  the  tubular  form  of 
the  bone  ? 

9.  What  advantage   in    the   spongy   character  of   the 
bones  at  the  ends  ? 


October]  ZOOLOGY.  79 

TO.  Can  you  see  any  means  by  which  the  bone  is  nour- 
ished ? 

IT.  Place  a  piece  of  bone  in  the  fire  and  thoroughly 
burn  it.  Put  it  on  live  coals,  and  let  it  remain  over 
night. 

12.  How  does  the  burnt  bone  differ  from   the  fresh 
bone  ? 

13.  After  the  burning  is  completed,  what  must  be  the 
nature  of  the  substance  remaining  ? 

14.  Place  another  small  bone  in  a  mixture  of  one  ounce 
of  hydrochloric  acid  to  a  pint  of  water.    Note  the  changes 
that  occur. 

15.  How  does  the  part  which  remains  unaffected  after 
a  day  or  two  differ  from  what  remains  after  burning  ? 
This  is  the  animal  matter  that  is  in  bone. 

1 6.  What  properties  of  bone  are  derived  from  the  min- 
eral matter  it  contains?     What  from  the  animal  matter? 

17.  Animal  matter  is  most  abundant  in  bones  in  early 
life,  and  mineral  matter  is  most  abundant  in  old  age. 

1 8.  When  are  bones  most  likely  to  be  distorted  ?    When 
most  easily  broken  ? 

19.  Why  will  bones,  distorted  for  some  time,  assume 
permanently  this  new  form  ? 

20.  What  school  habits  are  most  likely  to  distort  bones  ? 

21.  What  bones  most  frequently  suffer  distortion  ? 

22.  How  many  in  every  ten  people  that  you  know  are 
free  from  these  distortions  ? 

FAT— ADIPOSE  TISSUE. 

1.  Look  for  this  about  the  joint  and  muscle. 

2.  Squeeze  a  small  piece  between  the  fingers.    What  is 
obtained  ? 

3.  Can  you  think  of  any  use  for  it  ? 


8o  NATURE  STUDY.  [October 

THE  JOINT. 

1.  What   motions  are  possible  at  this  joint  ?     Locate 
those  joints  in  your  body  which  have  this  motion  only. 

2.  Such  are  called  hinge  joints.     Define  a  hinge  joint. 

3.  Find   the   cords   which   bind    the   bones   together. 
These  are  called  ligaments.     How  do  they  resemble  ten- 
dons ?     How  do  they  differ  from  them  ? 

4.  What  tissue  in  the  ligaments  ?     How  many  can  you 
find  at  this  joint? 

5.  Open  the  joint  with  a  knife.     Note  the  sticky  fluid 
found  inside.     It  is  called  Synovia,  or  the  Synovial  Fluid. 
What  use  can  you  discover  for  it  ? 

6.  With  your  knife  carefully  separate  the  ends  of  the 
bones  in  the  joint. 

7.  The  two  surfaces  which  rub  over  each  other  are 
called  the  articular  surfaces.     The  soft  translucent  tissue 
covering  these  surfaces  is  cartilage.     When  found  on  the 
ends  of  bones  in  a  joint,  it  is  called  articular  cartilage. 
The  meeting  of  two  bones,  as  in  a  joint,  is  called  an 
articulation, 

8.  Why  should  the  ligament  be  inelastic  ? 

9.  What  causes  a  sprained  joint  ?     How  is  the  joint 
injured  when  sprained  ? 

10.  What  must  take  place  in  a  dislocation  ? 

11.  What  occurs  in  a  stiffened  joint  ? 

12.  Review  these  lessons,  and  note  the  use  of  the  word 
tissue.     Can  you  write  a  definition  of  it  ? 


Botany 

Watch  the  plants  as  a  whole  as  the  season  changes. 
Note  the  disappearance  of  the  sap,  the  drying  of  the  leaf, 
the  maturing  fruit,  the  hardening  of  the  new  wood  in  the 
twig,  and  the  newly-formed  bud,  in  which  is  carefully 
packed  away  the  destiny  of  the  plant.  Animals  may 
hide  in  the  earth  or  flee  away  to  a  milder  clime, 
but  the  plant  must  face  the  blasts  of  winter  where  it 
stands,  and  it  prepares  itself  accordingly.  It  is  a  most 
interesting  phase  of  life.  Continue  to  collect  seeds  and 
nuts  of  all  kinds,  and  carefully  dry  and  preserve  them  in 
envelopes. 

1.  Examine  closely  a  branch,  and  find  out  how  and 
where    a   leaf   breaks    away  from    the    twig.     Does    the 
petiole  or  leaf-stalk  break  ?     What  kind  of  a  mark  or 
scar  remains  ? 

2.  Are   there  any  buds  newly  formed  ?     What  is   the 
relation  of  these,  in  position,  to  the  leaf? 

3.  Are  there  more  buds  than  one  to  the  leaf  ? 

4.  Can  you  find,  on  the  older  twigs,  buds  of  previous 
years  which  did  not  open  ? 

5.  What  influences  cause  the  leaves  to  change  color 
and  drop  off? 

6.  Does  the  bark  peel   readily  from  the  twig  ?     Is  it 
merely  drying  fast  to  the  wood  ? 

7.  How  much  new  wood  has  been  formed  this  year  ? 

8.  Where  has  it  grown,  in  the  center  or  at  the  circum- 
ference of  the  branch  ? 


82  NATURE  STUDY.  [October 

9.  Nuts,  and  the  seeds  of  most  weeds,  are  classed  as 
dried  fruits.     Why  is  it  they  are  uniformly  of  dull  colors  ? 

10.  Can  you  understand  why  the  edible  portion  of  nuts 
is  protected  by  a  shell,  while  in  berries  and  such  fruits  it 
is  not  so  covered  ? 

11.  What  animals  devour  nuts  ?     Do  they  in  any  way 
assist  in  scattering  them  ? 

12.  How  else  are  nuts  distributed  ?     Will  they  float  in 
water  ? 

13.  How  are  they  protected  while  unripe  and  on  the 
tree  ?     How,  when  they  open  and  fall  ? 

14.  Can  you  make  out  the  various  layers  of  the  ovary 
in  the  acorn,  hickory  nut,  walnut,  and  chestnut  ? 

15.  Is  the  form  of  the  nut  of  any  advantage  to  it  ? 

16.  Note  the  various  contrivances  by  which  the  seeds 
of  weeds,  etc.,  are  scattered.     How  do  some  manage  to 
use  the  wind  ?     What  part  of  the  flower  in  the  dande- 
lion and  thistle  becomes  the  sail  ? 

17.  What  sized  plants  bear  seeds  with  prickles  ?     Do 
you  see  the  reason  why  the    size  varies  within   narrow 
limits  ? 

1 8.  What  part  of  the  flower  becomes  the  prickle  ? 

19.  Are  the  prickles  in  any  case  fastened  to  the  seeds 
themselves  ? 

20.  If  the  seeds  are  caught  in  the  fur  or  hair  of  ani- 
mals, does  it  not  defeat  the  aim  of  the  plant  in  producing 
the  prickle  ? 

2 1 .  Examine  a  number  of  these  under  a  lens,  and  sketch, 
showing  the  structure. 

BOOKS  FOR  REFERENCE.  Humboldt  Library  :  No.  116,  chapter 
xi.  No.  33,  Vignettes  from  Nature,  chapters  xi,  xvi,  xvii,  xxi,  and 
xxii.  No.  64,  The  Distribution  of  Life.  No.  26,  chapter  xvii. 


EVAPORATION. 

1.  Place  small  amounts  of  water  in  various  shaped  ves- 
sels and  allow  them  to  stand  exposed  to   the  air  for  sev- 
eral days. 

2.  What  becomes  of  the  water? 

3.  Under  what  circumstances  will  it  evaporate  most 
rapidly  ? 

4.  Note  varying  effects  of  a  wide  extent  of  surface, 
depth,  currents  of  air  passing  over  the  surface,  surface 
protected  from  currents  as   in   a  corked  bottle,  direct 
sunlight,  darkness,  heat,  and  cold. 

5.  What  causes  mud  to  dry  up  ? 

6.  What  becomes  of  the  dew  ?     Frost  ? 

EBULLITION. 

1.  As  heat  is  added  to  a  vessel,  what  effect  is  there 
upon  the  rate  of  evaporation  ? 

2.  Note  the  changes  that  occur  as  the  water  comes  to 
the  boiling  point  ? 

3.  What  becomes  of  the  first  bubbles  ?     What  do  they 
contain  ? 

4.  What  causes  the  peculiar  noise  when  a  vessel  of 
water  simmers  ? 

5.  Note  the  bubbles  when  boiling  begins.     Where  do 
they  originate  ?     How  do  they  change  in  size  ?     Why  ? 

6.  What  are  these  bubbles  ? 

83 


§4  NATURE  STUDY.  [October 

7.  Hold  a  thermometer  in  the  steam  above  the  water  ; 
does  the  temperature  vary  after  boiling  begins  ? 

8.  Is  the  water  still-receiving  heat  from  the  flame  ? 

9.  What   becomes  of   this  heat  ?     If   you   hold   your 
hand  near  the  flame,  does  the  heat  continue  to  increase 
while  you   hold  it  there  ?     Why  does  it  not  in  the  same 
way  increase  the  temperature  of  the  water  ? 

10.  Try  boiling  alcohol.     Does  the  thermometer,  used 
as  before,  show  the  same  temperature  ? 

CONDENSATION. 

i  Where  does  the  water  go  when  the  mud  dries  up  ? 
Is  it  destroyed  ? 

2.  How  does  water  change  its   form  when   it  evapo- 
rates ?    What  is  its  form  before  it  evaporates  ?     (Liquid.) 
Afterward  ?     (Vapor.) 

3.  Is  it  visible  as  it  disappears  from  the  pan  by  evapo- 
ration ?     Explain  this. 

4.  Can  it  be  rendered  visible  ?    What  is  it. then  called  ? 

5.  What  change  takes  place  in  the  vapor  when  it  be- 
comes visible  ? 

6.  Explain  why  it  is  sometimes  foggy  in  the  mornings  ? 

7.  What  causes  the  fog  to  disappear  ? 

8.  Can  you  account  for  the  formation  of  clouds  ? 

9.  When  are  they  lowest  ?     Why  ? 

10.  What  is  the  history  of  a  drop  of  rain  ? 

DISTILLATION. 

Take  a  quart  or  more  of  the  "  hard  cider  "  produced 
by  the  fermentation  of  yeast.  (See  Chemistry  for  Sep- 
tember.) Put  it  into  a  retort  with  a  long  neck,  or  an 
ordinary  bottle  with  a  bent  glass  tube  fitted  tightly 
through  the  cork.  Suspend  this  in  a  vessel  of  boiling 


October]  PHYSICS.  85 

water,  and  conduct  the  vapor  through  the  tube  into  a 
small  bottle  partly  immersed  in  a  vessel  of  cold  water. 
Distil  until  about  one-third  has  passed  over  into  the  smaller 
bottle.  Redistil  until  alcohol  is  obtained  sufficiently 
pure  to  show  by  the  flame  test. 

1.  Why  is  the  smaller  bottle  immersed  in  cold  water  ? 

2.  Why  suspend  the  other  one  in  boiling  water  instead 
of  placing  it  next  the  flame  directly  ? 

3.  Does  the  liquid  in  the  flask  boil  ? 

4.  Why  not  boil  the  liquid  in  the  flask  ? 

5.  How  is  it  that  we  can  gradually  separate  the  alcohol 
from  the  remainder  of  the  liquid  by  this  process  ? 

6.  In  how  many  ways  does  the  alcohol  obtained  differ 
from  fresh  juice  of  the  fruit  from  which  it  was  distilled  ? 

7.  Try  burning  it  ;  taste  it  ;  note  the  odor  ;  allow  a 
little  to  evaporate  from  the  back  of  the  hand. 

8.  Compare  with  water. 

BOOKS  FOR  REFERENCE.     Humboldt  Library  :  No.  2,  Forms  of 
Water. 


SOLUTION. 

Provide  some  or  all  of  the  following  substances  :  com- 
mon salt,  alum,  saltpeter,  chalk,  washing  soda,  bichro- 
mate of  potash,  blue  vitriol,  copperas,  and  prussiate  of 
potash.  Each  pupil  should  have  a  small  bottle,  about  the 
size  of  the  one-eighth-ounce  morphia  bottle,  which  may 
be  procured  at  a  trifling  cost  of  any  druggist.  Fill  each 
nearly  full  of  cold  water  and  label.  Take  the  tempera- 
ture of  the  water,  before  beginning,  with  a  thermometer. 

1.  Drop  a  small   amount  of  the  different  substances, 
finely   powdered,  into  the  different  bottles.     What  be- 
comes of  it  ? 

2.  Drop  a  small  lump  in  ;  does  it  disappear  ?     Why  is 
the  disappearance  more  rapid  when  the  substance  is  finely 
powdered  ?     How  has  the  temperature  changed  ? 

Continue  to  add  the  finely  powdered  substance  with 
constant  stirring,  until  it  no  longer  disappears,  but  begins 
to  settle  on  the  bottom.  Gradually  warm  the  water  by 
placing  the  bottle  on  a  sand-bath.  If  not  heated  slowly 
the  bottle  will  crack.  Test-tubes  or  thin  glass  beakers 
are  much  better  for  this  purpose. 

3.  What  effect  does  the  heat  have  upon  the  substance 
at  the  bottom  ? 

4.  Add  more  of  the  substance   until   the  water  boils 
and  no  more  will  dissolve,  and  then  set  aside  to  cool. 

Those  substances  which  disappeared  in  the  water  are 

86 


October]  CHEMISTRY.  87 

said  to  be  soluble  in  water.  Water  is  a  solvent.  They  are 
said  to  dissolve,  and  the  mixture  of  water  and  the  dis- 
solved substance  is  a  solution. 

5.  Are  all  the  substances  named  soluble  ? 

CRYSTALLIZATION. 

Pour  a  little  of  the  above  solutions  while  hot  into  shal- 
low dishes,  and  set  aside  until  the  liquid  evaporates.  Sus- 
pend a  string  in  the  solution  remaining  in  each  of  the 
bottles,  and  observe  for  a  few  hours. 

1.  How  does  the  form  of  the  solid,  which  soon  appears, 
differ  from  what  was  added  to  the  water  ? 

2.  Do  the  crystals  which   form  in  the  solution  differ 
from  those  which  remain  after  evaporation  from  the  shal- 
low dishes  ? 

3.  Take  a  small  amount  of  a  solution  and  evaporate  it 
by  boiling  ;  how  does  the  rate  of  evaporation  affect  the 
crystals  ? 

4.  Are  the  crystals  of  each  substance  all  alike  ? 

5.  Solids  which  are  deposited  from  solution,  or  which 
solidify  from  a  melted  state  in  such  regular  forms,  are 
said  to  be  crystalline.     Those  which  solidify  without  the 
crystalline  form  are  amorphous. 


Meteorology 

1.  How  does  the  temperature  at  evening,   night,  and 
morning  compare  with  that  at  similar  times  during  Sep- 
tember ?     Will  the  changes  noted  in  any  other  column  of 
your  record  suggest  the  cause  for  this  ? 

2.  How  does  the  average  temperature  of  the  day  differ 
from  that  of  September  ? 

3.  What  is  the  direction  of  the  prevailing  wind  ?     Com- 
pare with  September. 

4.  How  has  the  prevailing  wind  affected  the  tempera- 
ture ? 

5.  Has  it  shown  any  marked  influence  upon  the  barom- 
eter ? 

6.  Has  it  brought  cloudy  or  clear  weather,  wet  or  dry  ? 

7.  From  what  direction  did  the  heaviest  rain  come  ? 
From  what   direction    did    the    greatest   number   come  ? 
Can  you  assign  reasons  for  this  ?     Consult  maps  and  the 
globe. 

8.  What  influences,  if  any,  has  the  nearest  mountain 
range  or  large  body  of  water  had  upon  the  temperature 
and  rainfall  ?     How  can  you  tell  what  their  influence  is  ? 

9.  What  kind  of  cloud  has  been  most  frequently  noted  ? 
Does  the  general  character  of  the  clouds  differ  from  that 
of  last  month  ? 

10.  Does  any  particular  kind  of  cloud  usually  imme- 
diately precede  a  heavy  rain  ? 

11.  Have  you  noticed  any  fogs  ?     When  are  they  most 
dense  ?    At  what  time  do  they  disappear  ? 


October]  METEOROLOGY.  89 

12.  In  what  regions  are  they  most  dense  ? 

13.  What  was  the  character  of  the  day  and  night  pre- 
ceding the  fog  ? 

14.  Does  it  always  follow  rain  ? 

15.  What  becomes  of  it  when  it  is  dissipated  ? 

STUDY  OF  THE  WEATHER  BUREAU  MAPS. 

1 6.  Compare  the  temperature  of  the  "  Low  "  with  that 
of  the  "  High  "  area.     Can  you  account  for  the  exceptions 
to  the  rule  ? 

17.  Does  the  heaviest  rainfall,  as  given  on  the  margin 
of  the  map,  accompany  the  "  Low  "  area  ? 

1 8.  Do   the   isotherms   show   as   marked    a   deviation 
from  the  general  direction   as  they  did  in   September  ? 
Do  the  deviations  occur  in  the  same  regions  ? 

19.  What  is  the  direction  of  the  wind  with  respect  to 
the  "  High  "  area  ? 

20.  Where  was  the  storm  center  during  the  heaviest 
storm  in  this  region  for  the  month  ? 


Hetronom^ 


1.  What  change  noticed  in  the  length  of  day  and  night  ? 

2.  Compare  with  the  change  during  September. 

3.  Compare  with  the  change   in  position  of  the  noon 
shadow. 

4.  Are   the  spaces   between    two  successive  marks  of 
the  same  length  as  they  were  in  September  for  the  same 
period  of  time  ?     Can  you  show  why  there  is  variation  ? 

5.  Using  the  globe  and  sun,  explain  the  differences 
discovered. 

6.  What    time   elapses    between    two    successive   full 
moons? 

7.  By  means  of  a  globe  and  sun,  and  another  object  to 
represent  the  moon,  show  what  the  relative  position  of 
the  three  bodies  is  when  the  moon  is  full. 

The  constellations  to  be  observed  are  all  of  those  given 
in  preceding  month,  and  in  addition  :  Perseus,  Androm- 
eda, Serpentarius.  Note  the  change  in  position,  since 
last  month,  of  the  different  constellations. 

How  can  we  account  for  it  ? 


DRAINAGE. 
GENERAL   CONDITIONS. 

1.  What  becomes  of  the  water  that  falls  as  rain  upon 
the  land  ?     Mention   three  ways  by  which  it  is  removed 
from  the  surface.     (See  Physics  and  Geology  for  Octo- 
ber.) 

2.  What  determines  the  direction  of  the  flow  of  waters 
from  the  land  ? 

3.  What  conditions  determine  its  velocity  ? 

4.  What  conditions  affect  the  size  of  a  river,  (a)  its 
length,  (b)  its  volume  of  water  ? 

NORTH  AMERICA. 

1.  Which   ocean,    with    its    arms,    receives    the    larger 
amount  of  water  from  the  continent  of  North  America? 

2.  What  does  this  indicate  as   to   the  number  of  the 
great  slopes  of  the  continent  ? 

3.  Where  do  they  show  the  line  of  the  great  continen- 
tal water-parting  to  be  ? 

4.  By  modeling,  represent  the  continental  outline  with 
this  great  water-parting  and  the  two  slopes. 

5.  Do  the  rivers  in  the  eastern  slope  indicate  the  posi- 
tion of  a   secondary  water-parting  ?     What  is  its  direc- 
tion and  position  ?     Represent  the  two  slopes  from  this 
water-parting. 

9* 


9 2  NATURE  STUDY.  [October 

6.  Judging  from  the   direction   of  the   rivers   in    the 
northern  slope,  where  are  the  great  depressions  ? 

7.  Are  there  any  minor  divisions  in  the  slope,  as  indi- 
cated by  rivers  ? 

8.  In   the   southern    slope    of   the   continent,  do   the 
rivers  indicate  any  other  water-parting  ? 

9.  Where  is  this,  and  what  is  its  direction  ?     Indicate  it 
in  the  model. 

10.  What  directions  do  the  rivers  flow  from  this  water- 
parting  ? 

J  i.  Where  is  the  lowest  line  between  the  great  conti- 
nental water-parting  and  the  last  one  found  ? 

12.  Study  the  course  of  the  rivers  in  the  southern  conti- 
nental slope  between  these  two  water-partings  ;  what  must 
be  the  general  form  and  character  of  the  surface  of  this 
region  ? 

13.  What  things  contribute  to  form  the  great  rivers  of 
this  region  ?     (See  Studies  of  Signal  Service  Maps.) 

14.  In  the  eastern  half  of  the  Mississippi  basin,  is  there 
any  well-marked  transverse  water-parting  ? 

15.  Compare  the  two  halves  of  the  basin  in  this  re- 
spect. 

1 6.  Since   no   great  river  systems  are   found   on  the 
coast  slopes,  what  must  be  the  character  of  those  slopes  ? 
What  is  their  direction  from  the  water-partings  ? 

17.  Make  a  complete  model  of  the  continent,  showing 
the  water-partings  and  slopes,  the  lines  of  lowest  depres- 
sion, the  chief  rivers  and  lakes. 

1 8.  In  what  way  did  the  continental  slopes  affect  the 
settlement  of  the  country  ? 

19.  Why  were  the  earliest  settlements  in  the  interior 
made  along  the  northern  border  of  the  United  States  ? 

20.  What  advantages  did  the  early  French  routes  into 


October]  GEOGRAPHY.  93 

the  interior  possess  over  those  of  the  English  and  Span- 
ish ? 

21.  In  what  way  have  the  different   slopes  affected  the 
occupations  of  the  people  ? 

22.  Why  has  the  Atlantic  coast  slope  always  been   a 
manufacturing  region  ? 

23.  Why  does  New  York  excel  Philadelphia  in  trade 
with  the  interior  ? 

24.  What   has   determined   the   location   of  the  great 
cities  of  the  Mississippi  basin  ? 

25.  What  natural  features  have  fixed  the  chief  routes  of 
commerce  ?     (The  line  where    the    slopes  meet  at  their 
lower  edges  or  borders.) 

26.  How  do  the  continental  slopes  affect  the  commerce 
between  the  North  and  South  ? 

27.  How  do  the  slopes  affect  the  commerce  between 
the  East  and  West  ? 

28.  How  have  the  great  slopes  affected  the  develop- 
ment of  the  Pacific  coast  region  ? 

29.  HOW  have  the  continental  slopes  affected  the  com- 
merce between  the  Atlantic  and  Pacific  coasts  ? 

BOOKS  FOR   REFERENCE.     How  to  Study  Geography,  Francis  W. 
Parker  ;  Earth  and  Man,  Guyot. 


EROSION  AND  SEDIMENTATION. 

Select  some  small  stream  that  may  be  studied  for  some 
distance  along  its  course.  The  small  gullies  formed  by 
a  heavy  shower  will  answer  very  well.  Certain  river  val- 
leys in  northern  Italy  that  were  once  partially  filled  with 
glacial  drift  njw  abound  in  stone-capped  clay  pillars 
many  feet  in  height.  These  have  been  formed  by  the 
rain  wearing  away  the  earth  around  the  stones  while  that 
immediately  under  them  was  protected  from  its  action. 
Similar  pillars  in  miniature  may  be  seen  after  a  hard  rain 
on  any  exposed  clayey  surface  where  there  are  small  bits 
of  stone.  The  height  of  the  pillars  indicates  roughly  the 
amount  of  soil  torn  away  by  the  rain.  The  sun  then 
dries  them  out,  and,  crumbling  down,  they  are  soon  again 
at  a  common  level  with  the  surface.  Trifling  as  this  pro- 
cess may  seem,  the  amount  of  soil  thus  beaten  up  and  re- 
moved by  the  rain,  in  the  course  of  a  year,  must  be 
enormous. 

1.  How  does  a  heavy  rain   affect  the  surface  of  the 
ground  ?     How  do  you  account  for  any  minute  elevations 
that  remain  standing  after  a  hard  rain  ? 

2.  What  causes  a  stream  to  be  crooked  ?     Does  it  ever 
tend  to  straighten  its  channel  ?     How  ? 

3.  In  what  part  does  it  cut  the  deepest  channel  ? 

4.  In  what  part  the  widest  ? 

94 


October]  GEOLOGY.  95 

5'.   Upon  what  does  the  swiftness  depend  ? 

6.  When   two   branches  unite,   is   the    single   channel 
thus  formed  as  large  as  that  of  both  branches  put  to- 
gether ? 

7.  Can   you    notice    any   difference    in    the  character 
of  the  sediment  in  different  parts  of  the  course  ?     Dip  up 
a  little  of  the  water  in  different   places  and  allow  it  to 
settle. 

8.  In  what  part  of  the  course  of  the  stream  do  you  find 
the  largest  pebbles  ? 

9.  Where  are  they  most  rounded  and  worn  ? 

10.  What  determines  where  in  the  course  of  a  stream 
they  shall  be  deposited  ?     Study  the  order  of  deposition 
in  a  pool  or  lakelet.     As  a  further  illustration,  shake  up 
different  kinds  of  material  in  a  glass  jar,  and  allow  them 
to  settle. 

n.  In  what  part  of  the  stream's  course  is  the  finest  mud 
dropped  ? 

12.  Does  the  stream  build  new  material  along  its  banks  ? 
Under  what  conditions  ? 

13.  Cut  down  through  some  of  the  material  thus  de- 
posited, and  note  the  arrangement  ;  is   there  any  regu- 
larity ? 

14.  Examine  the  material  deposited  at  the  mouth  of  the 
stream  ;  how  is  it  arranged  ? 

15.  Under  what  conditions  will  it  not  be  deposited  ? 

16.  What  are  some  of  the  things  which  assist  the  stream 
in  widening  its  channel  ?     What  influence  does  drift  have 
upon  it  ? 

17.  What  causes  the  formation  of  waterfalls  ? 

1 8.  What  determines  whether  the  descent  from  a  higher 
to  a  lower  level  shall  be  by  a  cascade  or  by  rapids  ? 

19.  Study  the  face  of  some  cliff,  a  railroad  cut,  the  sides 


96  NATURE  STUDY.  [October 

of  a  trench,  or  newly  made  excavation  ;  is  there  evidence 
of-  deposition  from  water  ? 

20.  Can  you  tell  whether  it  was  deposited  by  running 
or  still  water  ? 

21.  Can  you  see  any  reason  why  certain  rocks  are  to  be 
found  in  strata  ? 

22.  Can  you  tell  if  the  rocks  that  dip  were  deposited 
in  that  position  ?     Compare  with  the  depositions  in  the 
glass  jar.     (See  10.) 

23.  If  not  deposited  thus,  what  evidence  is  there  that 
they  were  uplifted  ? 

24.  Did  the  upheaving   force  act   slowly  for  a  great 
length  of  time,  or  rapidly  for  a  shorter  period  ? 


Gather  a  handful  of  coarse  sand.  Put  it  into  a  jar  and 
thoroughly  wash  by  shaking  it  up  with  water  repeatedly, 
until  freed  from  silt. 

1.  Examine  some  of  the  grains  under  a  lens  ;  can  you 
find  any  crystals  ? 

2.  Are  they  entire  or  fragmentary  ? 

3.  How  many  different  kinds  can  you  find  ? 

4.  Can  you  tell  where  the  sand  came  from  ? 

5.  Examine  particles  of  the  soil  and  compare  with  a 
bit  of  the   powdered  rock  which  underlies  it  ;  are  they 
the  same  ? 

6.  Has  the  soil  been  formed  by  the  weathering  or  rot- 
ting of  the  underlying  rock  ? 

7.  What  other  agent  has  aided  in  the  soil  formation  ? 

8.  Examine  the  rough  surface  of  a  piece  of  marble  ; 
can  you  see  any  crystals  ? 

9.  In  the  same  way  examine  a  piece  of  granite  ;  how 
many  different  minerals  does  it  contain  ? 

10.  Coarsely  powder  a  small  piece  ;  are  the  fragments 
crystalline  ?     Which  is  the  softest  ?     Which  the  hardest  ? 
Granite  is  made  up  of  quartz,  feldspar,  and  mica  ;  the 
feldspar  decomposes  and  becomes  clay.     What  becomes 
of  the  quartz  ? 


97 


Zoology 

There  is  hardly  a  more  useful  auxiliary  to  the  science 
work  which  relates  to  animal  life  than  an  aquarium.  If 
it  be  possible  to  have  a  strong  metal-framed  one  connect- 
ed with  a  steady  water  supply,  it  will  save  much  trouble, 
but  one  may  be  managed  very  well  without  such  con- 
veniences. If  no  connection  with  pipes  can  be  made,  it 
it  better  to  have  several  of  medium  size  than  to  have  one 
large  one.  Fish  globes,  eight  or  ten  inches  in  diameter, 
are  inexpensive  and  will  be  found  very  useful. 

A  small  aquarium  may  be  made  thus  :  use  an  inch 
board  one  foot  wide  and  one  foot  long  for  the  bottom, 
and  two  boards  of  the  same  thickness  and  width,  ten 
inches  high,  for  the  ends.  Three-eighths  of  an  inch  from 
the  edge  on  either  side,  with  a  saw,  make  a  groove  one- 
quarter  of  an  inch  deep,  and  wide  enough  to  receive 
loosely  double  strength  glass.  Groove  the  end  boards 
and  fasten  them  to  the  bottom  with  screws  so  that  the 
grooves  will  exactly  match.  Partially  fill  the  grooves 
with  soft  putty,  or  better,  aquarium  cement,  and  press 
into  each  side  a  pane  of  glass.  By  making  the  bottom 
board  eleven  and  one-half  inches  long,  an  ordinary  ten 
by  twelve  window  pane  will  be  the  proper  size.  When 
the  glass  is  pressed  to  the  bottom  of  the  groove,  draw  the 
two  ends  in  at  the  top  until  the  glass  is  held  firmly  and 
then  fasten  them  in  place  by  narrow  strips  of  wood, 
one  on  each  side  of  the  tank,  placed  on  top  of  the  glass 
and  screwed  to  the  end  pieces.  These  strips  also  pro- 

98 


November]  ZOOLOGY.  99 

tect  the  hands  from  injury  while  working  with  the  speci- 
mens in  the  aquarium.  Before  filling  with  water,  the 
inner  surface  of  the  bottom  and  ends  should  be  well 
rubbed  with  oil  or  paraffine  and  the  grooves  inside  the 
glass  well  packed  with  putty.  The  bottom  should  be 
covered  with  an  inch  or  two  of  sand  and  coarse 
gravel. 

Two  or  three  of  this  size  will  enable  one  to  preserve 
safely  a  large  variety  of  specimens,  and  sufficient  in 
amount  to  keep  up  an  interesting  study  of  animal  life 
throughout  the  winter.  Indeed,  if  the  supply  falls  short, 
they  may  be  restocked  at  any  time  of  the  year.  By  drag- 
ging the  bottom  or  edges  of  a  pond  or  ditch,  which  is 
covered  with  leaves  and  grass,  with  a  hand  rake,  using  a 
net,  one  may  usually  in  the  midst  of  winter  gather  an 
abundance  of  minnows,  tadpoles,  snails,  crawfish,  frogs 
water-beetles,  etc. 

GENERAL  OBSERVATIONS. 

1.  Are  any  birds  to  be  found  at   this  time  ?     Are  the 
birds  that  have  migrated  superior  to  those  that  remain  in 
intelligence  ? 

2.  Are  they  winter  residents  ? 

3.  Have  they  been  here  all  the  year  or  have  they  come 
from  some  other  locality  ? 

4.  What  is  their  food  ?     How  do  they  find  protection 
from  storms  ? 

5.  Where  do  they  stay  at  night  ? 

6.  Is  their  winter  garb  different  from  that  of  summer  ? 

7.  Are  they  mated,  in  flocks,  or  solitary  ? 

8.  Look  for  insects  under  stones,  boards,  leaves,  etc. 
Have  they  lined  their  nests  in  any  way  as  a  protection 
against  the  cold  ? 


NATURE  STUDY.  [November 


9.  If  they  are  not  active  keep  them  for  a  short  time 
in  a  warm  room. 

10.  Do  they  show  signs  of  life  ? 

n.  In  the  same  way,  search  for  earthworms. 

12.  What  substitute  have  these  animals  for  migration  ? 

13.  What  do  they  do  for  food  ? 

14.  Animals  lying  through  the  winter  in  a  dormant 
state  are  said  to  hibernate. 

15.  Pat  a  common  mud-turtle  in  a  box  of  wet  sand 
and  cover  loosely  with  a  lid.     Keep  the  sand  wet. 

16.  Note  the  time  when  he  disappears  ;  he  will  prob- 
ably not  be  seen  again  for  months. 

17.  How  do  you  think  the  chances  for  life  of  a  hiber- 
nating animal  compare  with  one  that  is  migratory. 

18.  Why  does  the  animal   hibernate  when   kept  in  a 
warm  room  in  winter  time  ?     Does   the  animal  display 
intelligence  in  hibernating  ? 

ANIMAL  COVERINGS  AND  WARMTH. 

1.  What  changes  do  we  make  in  our  clothing  as  winter 
approaches  ?     In  material  ?     Color  ?     Thickness?     Tex- 

ture ? 

2.  How  do  the  brute  animals  make   similar   prepara- 

tion ? 

3.  Is  the  winter  plumage  of  birds  the  same  as  that  of 
summer  ? 

4.  How  do  birds  preen  their  feathers  ?    Why  ? 

5.  How    are  the  coverings    of  water-fowl    especially 
adapted  to  their  mode  of  life  ? 

6.  Study  the  arrangement  of  the  feathers  on  a  bird  ;  a 
pigeon  or  sparrow  may  be  readily  obtained  for  the  pur- 
pose.    Are    the    feathers    distributed   evenly    over    the 
body? 


November]  ZOOLOGY.  IOI 

7.  Is  there  any  obvious  advantage  in   the  manner  in 
which  the  feathers  are  distributed  ? 

8.  Mention  the  uses  you  can  see  for  feathers  ? 

9.  What  animal  can  you   name  that  is   covered  with 
fur?     Name  one  covered  with  hair?      What  difference 
is  there  between  fur  and  hair  ?     Examine  a  dog  and  a 
cat. 

10.  Can  you  suggest  any  reason  why  one  animal  is  pro- 
vided with  fur  and  another  with  hair  ? 

n.  Which   is    the   better    protection   against   injury? 
Which  is  the  warmer  covering  ? 

12.  Where  are  fur-bearing  animals  found  ?     Where  are 
those  with  a  hairy  covering  found  ?     Compare  wool  with 
both  hair  and  fur  ? 

13.  Read  something  of  the  history  and  habits  of  the 
fur  and  wool  bearing  animals. 

14.  Study  the  scales  of  a  fish  and  snake  ;  what  is  their 
chief  use  in  each  case  ? 

15.  Do  the  coverings  of  fishes  and  snakes  change  in 
any  way  with  the  seasons  ? 

16.  If  possible,  secure  a  snake  skin  that  has  been  shed 
and  examine  it  closely  ;  how  does  the  snake  get  out  of  it  ? 
Are  the  scales  shed  ? 

17.  Is  the  right  side  out  ?     Note  the  transparent  cover- 
ing that  was  over  the  eye. 

1 8.  How  does  the  covering  of  the  turtle  differ  from 
that  of  both  the  snake  and  the  fish  ? 

19.  Do  insects  have  skins  ?     How  does  the  outside  of 
an  insect's  body  differ  from  most  other  animals  studied  ? 

20.  What  peculiarity  in  the  covering  of  a  crawfish  ? 
What  is  its  most  important  use  ? 

21.  Can   you   see  how  it  is  possible  for  the  animals 
which  have  such  hard  coverings  to  grow  ? 


102  NATURE  STUDY.  [November 

22.   How  do  the  different  modes  of  life  of  the  various 
animals  observed  correspond  to  their  coverings  ? 

THE  SKIN  OF  THE  HUMAN  BODY. 

1.  Compare  the  skin  on  the  back  of  the  hand  with  that 
on  the  palm  in  color,  thickness,  sensitiveness,  and  mark- 
ings. 

2.  Why  is  the  greater  thickness  on  the  palm  ? 

3.  On  what  other  parts  of  the  body  is  the  skin  similar 
to  this  ?     Why  ? 

4.  What  is  the  effect  of  manual  labor  on  the  skin  in  the 
palm  ? 

5.  Is  there  any  difference  in  the  causes  which  operate 
on  the  palm  and  on  the  sole  of  the  foot  ? 

6.  What  causes  the  creases  in  the  palm  ? 

7.  Note  the  short  hairs  covering  the  back  of  the  hand  ; 
examine  with  small  magnifying  glass.     At  the  root  of  each 
hair  is  a  small  oil  gland  which  pours  out  upon  the  surface 
a  minute  quantity  of  oil.     Notice  the  softness  and  flexi- 
bility of  the  skin. 

8.  When  is  it   that   the   skin  on   the  hands   becomes 
harsh  and  chapped  ? 

9.  How  is  oil  affected  by  cold  weather  ?     How  must  it 
affect  the  flow  from  the  glands  in  the  hands  ? 

10.  How  do  the  hands  feel  after  having  had  them  in 
soap-suds  ?     What  must  be  the  effect  of  the  soap  on  the 
oil? 

11.  Why  should  the  skin  be  wiped  dry  after  washing? 

12.  What  is  the  best  way  to  prevent  the  hands  from 
becoming  chapped  ? 

13.  What  would  you  suggest  as  the  natural  remedy  ? 
The  outer  layer  of  the  skin  which  sometimes  may  be 

rubbed  up  as  white  scales,  and  which  forms  the  clear  skin 


November]  ZOOLOGY.  103 

in  a  blister,  is  the  cuticle  or  scarf  skin.  As  it  dies  and 
is  worn  off  it  is  replaced  by  the  true  skin  underneath. 
When  dry,  it  cracks  and  exposes  the  sensitive  layer  lying 
under  it. 

A  small  cake  of  pure  mutton  tallow  rubbed  over  the 
hands  at  night  is  a  simple  and  effective  remedy.  It 
should  not  be  smeared  on  in  great  quantity.  Nature 
never  oils  the  skin  in  that  way,  and  we  should  imitate  her 
in  this  respect. 

14.  What  is  perspiration  ?     Is  it  pure  water  ? 

15.  What  causes  tend  to  increase  perspiration  ?     To 
diminish  it  ? 

16.  Passing  outward  through  the  skin,  and  opening  at 
its  surface,  are  very  many  minute  tubes  that  convey  the 
perspiration  from  the  sweat  glands  ;  these  are  situated  in 
the  deeper  layers  of  the  skin.     The   openings  of  these 
glands  may  be  seen  through  a  magnifying  glass  in  rows  in 
the  palm. 

The  sweat  glands  in  health  are  continually  throwing  off 
from  the  body  waste  matters  which  are  carried  to  them 
by  the  blood. 

17.  How  must  the  heat  of  the  body  be  affected  by  the 
evaporation  of  perspiration  from  its  surface  ? 

1 8.  Do  you  become  warmer  or  cooler  when  you  per- 
spire freely.     Since  the  skin  thus  assists  in  maintaining  a 
proper  heat  in  the  body,  it  is  a  heat  regulator. 

19.  Rub  a  little  oil  briskly  on  the  hand  ;  what  becomes 
of  it  ?     Has  it  evaporated  ? 

20.  Why  is  it  that   liniments  may  be  applied  to  the 
skin  for  ailments  that  lie  deeper,  as  in  case  of  a  sprain  ? 
The  skin  is  an  organ  of  absorption. 

21.  On  what  part  of  the  body  is  the  skin  most  useful 
in  giving  us  the  sense  of  touch  ? 


104  NATURE  STUDY.  [November 

22.  The  sensitiveness  of  the  skin  in  different  parts  may 
be  tested  by  using  a  pair  of  dividers  with  sharp  points 
thus  :  close  the  eyes  and  allow  some  one  to  touch  the 
skin  in  various  places,  now  with  the  single  point,  then 
with  the  double  point.     Find  where  you  can  distinctly 
distinguish  the  two  points  when  they  are  closest  together. 

23.  Try  in  this  way  the  palm,  back  of  hand,  cheek, 
tongue,  lips,  back  of  neck,  arm,  ear,  etc. 

24.  How  many  important  uses  have  we  found  for  the 
skin? 

25.  Examine  one  of  the  finger-nails.     Note  the  opaque 
area  near  the  base  called  the  lunula,  and  also  how  the 
skin  is  attached  around  the  inner  end. 

26.  Does    the   skin    grow   fast   to   the   edge   of    the 
nail  ? 

27.  Why  does  the  skin  sometimes  break  and  peel  back- 
ward from  the  base  of  the  nail  ? 

28.  To  prevent  this,  loosen  the  skin  by  running  around 
the  edge  the  dull  point  of  a  knife. 

29.  In  what  way  are   the   nails    most   useful  ?     What 
happens   if   they   are   allowed   to   grow    too   long  ?      If 
trimmed  too  closely  ?     How  does  the  care  of  the  nail 
affect  the  shape  of  the  finger-tips  ? 

30.  How  does  biting  the  finger-nails  spoil  them  ? 

31.  Why  is  a  knife  better  than  scissors  for  trimming 
them  ?     The  nail  is  made  of  thin  layers,  and  scissors,  es~ 
pecially  dull  ones,  tend  to  separate  them. 

32.  Of  what  use  to  us  is  the  hair  on  the  head? 

33.  Can  you    give   a   good   reason   for  brushing  and 
combing  it  ? 

34.  Note  the  white  powdery  flakes  that  may  be  some- 
times brushed  from   the   head.     Where   do   they  come 
from  ? 


November]  ZOOLOGY.  105 

35.  Compare   these    with    the   cuticle   which    may  be 
rubbed  from  the  back  of  the  hand. 

36.  What  gives  the  softness  and  flexibility  to  the  hair  ? 

37.  What  is  the  effect  of  using  soap  and  water  upon  it  ? 
Why  is  it  so  ? 

38.  Why   is   it   necessary  to  wash   the  hair  ?     If   the 
scalp  is  healthy  no  oil  is  needed  ;  and  if  it  is  not,  oil  will 
do  but  little  good.     Treat  the  scalp  much  the  same  as 
you  do  the  skin  on  other  parts  of  the  body. 

39.  How  many  distinct  uses  of  the  skin  maybe  named  ? 

40.  How  may  it  best  be  cared  for  as  an  organ  of  pro- 
tection ?     Contrast   the   effects   of   indoor   and   outdoor 
occupations  upon  it.     What  are  the  effects  upon  the  skin 
of  bodily  exercise  in  fresh  air  ? 

41.  How  may  its  usefulness  as  an  organ  of  touch  be 
increased  ? 

42.  In  what  occupations  is  a  refined  sense  of  touch 
necessary  ?     Of  what  use  is  it  to  a  physician  ?     How  do 
the  blind  utilize  it  ? 

43.  Test  yourself  as  to  this  sense.    Can  you  distinguish 
by  touch  a  one-cent  piece  from  a  dime  ?    A  five-cent 
piece  from  a  two-cent  piece  ?     Sugar  from  salt  ?     Salt 
from  sand  ?     Can  you  distinguish  flannel  from  heavy  cot- 
ton cloth  ?     Printed  from  unprinted  paper  ? 

44.  How  is  the  usefulness  of  the  skin  promoted  by 
bathing  ? 

45.  How  does  the  work  of  the  skin  necessitate  frequent 
change  of  clothing  ? 

BOOKS  FOR  REFERENCE.  As  a  text-book,  Martin's  Human  Body. 
Humboldt's  Library,  No.  4,  Man's  Place  in  Nature.  See  also  the 
Nos.  previously  recommended  in  work  for  September  and  October. 


SSotan?, 

The  activity  of  plant  life  outdoors  has  ceased,  and 
but  little  can  be  done  with  the  study  this  month  except 
to  examine  the  dormant  condition  of  those  plants  which 
live  through  the  winter,  and  to  note  the  provisions  made 
for  the  succeeding  season  by  those  that  do  not.  The 
nice  adaptation  of  the  plants  to  their  changed  environ- 
ments is  the  chief  point  to  be  observed. 

1.  Have  the  plants  completed   their   preparation  for 
winter  ? 

2.  Can  you   find  any  that  continue  to  grow  until  the 
leaves  fall? 

3.  Do  the  first   frosts   kill    any   of  the   newly  grown 
twigs  ?     Examine  as  many   different  kinds  of  trees  as 
possible. 

4.  What  changes  have  the  new  twigs  undergone  since 
summer  ? 

5.  Can  you  find  any  plants   that  have  been   entirely 
killed  ? 

6.  How  will  such  plants  be  reproduced  next  season  ? 

7.  How  does  the  number  of  seeds  produced  by  plants 
that  are  killed  each  year  by  frosts  compare  with  the  num- 
ber produced  by   plants  that  live   from   year  to  year  ? 
Which  class  of  plants  seems  to  have  the  better  mode  of 
scattering  its  seeds?     Take  plenty  of  time  in  working  up 
this  topic  so  that  a  large  number  of  examples  can  be 
cited  by  the  pupils. 

8.  Are  there   any  seeds  to  be  found  ?     Can  you  find 

106 


November]  BOTANY.  107 

any  which  by  some  means  have  been  planted  ?  Re- 
move a  small  pan-full  of  earth  to  the  warm  school-room 
and  see  if  any  self-planted  seeds  will  grow. 

9.  Can  you  find  any  plants  which  came  from  the  seed 
last  spring  that  have  been  entirely  killed  by  the  frost  ? 
Such  plants  are  called  annuals. 

10.  Plants  which  live  over  from  year  to  year  are  called 
perennials. 

11.  Look  through  the  garden  for  plants  whose  roots 
or  underground  stems  are  still  alive,  but  whose  tops  may 
be  dead.     Do  you  know  what  the  entire  life  history  of 
such  a  plant  is  ?     Examples,  parsnip  and  turnip.     Such 
plants  are  called  biennials. 

REFERENCES.    See  October. 


HEAT. 

In  the  experiments  to  be  performed,  it  is  the  intention 
to  have  the  pupils  prepare  the  apparatus  under  the  di- 
rection of  the  teacher  and  do  all  the  work. 

The  teacher  must  see  that  the  directions  are  closely 
followed  that  the  conditions  may  be  as  nearly  perfect  as 
possible.  Ideal  results  are  not  to  be  expected,  but  for 
what  is  lost  in  this  respect,  compensation  may  often  be 
found  in  a  close  study  of  the  disturbing  elements  which 
rendered  them  inaccurate.  Interpretation  of  the  results 
of  all  the  experiments  must  be  insisted  upon,  and  con- 
cise statements,  together  with  descriptions  of  the  appa- 
ratus, in  many  cases  accompanied  with  drawings,  should 
be  required. 

In  some  instances,  teachers  fail  because  they  do  not 
allow  the  pupils  sufficient  time  in  which  to  prepare  their 
apparatus.  With  the  mind  fixed  upon  an  expected  result, 
they  too  often  force  the  experiment  regardless  of  proper 
precautions  which  should  have  been  taken.  In  describing 
an  experiment  the  pupil  should  always  be  required  to 
state  what  precautions  are  necessary  to  be  observed. 
There  is  as  much  for  the  pupil,  often,  in  the  careful  prep- 
aration and  manipulation  of  the  apparatus  as  there  is  in 
the  outcome  of  the  experiment  itself, 

In  the  following  work,  with  a  little  care  on  the  part  of 

108 


November]  PHYSICS.  109 

the  teacher,  a  good  deal  may  be  accomplished  in  the  cul- 
tivation of  a  "  temperature  sense  "  in  the  pupil.  While 
it  does  not  rank  high  among  the  senses  in  usefulness,  and 
in  most  persons  it  is  but  poorly  developed,  it  should  not 
by  any  means  be  neglected.  With  but  little  practice  the 
pupils  will  be  able  to  judge,  with  considerable  accuracy, 
of  the  different  degrees  of  temperature  of  water  between 
the  freezing  point  and  that  of  130°  or  140°  Fahren- 
heit. 

The  central  thought  to  be  developed  in  these  lessons 
on  heat  is,  that  heat  is  energy  which  expresses  itself  in 
different  ways  owing  to  the  manner  in  which  it  is  directed 
and  to  the  medium  employed.  Almost  the  only  expres- 
sion with  which  the  pupils  are  familiar  is  that  of  temper- 
ature, and  that  heat  should  be  able  to  perform  work 
without  increasing  the  temperature  is  something  that  is 
hard  to  get  them  to  realize.  The  fact,  however,  that 
heat  continually  passing  into  a  vessel  of  melting  snow  or 
ice  does  not  raise  the  temperature  while  the  ice  is  melting 
is  enough  to  start  them  to  thinking  in  an  intelligent  way 
upon  the  subject.  The  uniform  temperature  of  water 
after  it  has  been  raised  to  the  boiling  point,  although  heat 
is  constantly  added,  is  illustrative  of  the  same  point.  To 
the  question  as  to  what  this  excess  of  heat  which  passes 
into  the  water,  in  either  case,  does,  the  pupil  can  hardly 
find  a  wrong  answer,  if  cautiously  and  properly  directed. 

RADIATION,  ABSORPTION,  AND  REFLECTION. 

i.  Heat  an  iron  rod  or  bar  in  a  flame  till  red  hot,  re- 
move, and  hold  the  face  or  hand  near  it  on  different 
sides.  What  is  noticed  as  to  the  direction  in  which  heat 
passes  off  ?  Heat  thrown  from  a  body  thus  is  said  to  be 
radiated. 


HO  NATURE  STUDY.  [November 

2.  What  becomes  of  the  heat  radiated  from  a  body  ? 
Is  it  destroyed  ? 

3.  Does  the  rod  radiate  all  its  heat  ?     When  will  radia- 
tion cease  ? 

4.  By  what  contrivances   are  rooms   heated   by  radia- 
tion  ? 

5.  Why  does  the  earth  become  cooler  after  sunset  ? 

6.  Which  becomes  cold  faster,  the  land  or  the  water? 

7.  Why  is  it  that  dew  forms  at  nightfall  ? 

8.  Why  is  the  formation   of  dew  dependent  upon  the 
clearness  of  the    night?     Consult    your    Meteorological 
Record  for  the  facts  upon  which  to  base  your  answer. 

9.  Compare  and  contrast  with  (8)  the  conditions  under 
which  fog  forms. 

10.  When  any  body  is  held  near  a  warmer  one,  how  is 
the  former  affected  by  the  latter  ?  Anything  so  warmed  is 
said  to  get  its  heat  by  absorption. 

11.  Is  the  absorption  of  heat  affected  by  the  smooth- 
ness or  roughness  of  the  surface  of  the  body  ? 

12.  Does  color  affect  the  result  ?     When  opportunity 
offers,  spread   two  small  squares  of  cloth,  one  white  and 
the  other   black,  upon  snow  in  the    sunshine  ;    after  a 
time  notice  the  rate  of  melting  underneath  each  one.    Try 
different  materials  of  each  color  ;  is  the  rate  of  melting 
dependent  upon  the  color  or  material  and  texture  of  the 
cloth  ? 

13.  Heat  which  strikes  a  body  and  is  again  thrown  off 
is  said  to  be*  reflected. 

14.  Are  good  radiators  also  good  reflectors  ? 

15.  Are  good  radiators  good  absorbers  ? 

16.  Which  of  the  above  qualities  should  a  good  stove 
possess  ? 

17.  Should   a  stove   be   kept  with  a  brightly  polished 


November]  PH  YS1CS.  1 1 1 

surface  ?     Should   the   surface  be  smooth  or  broken   by 
ornamentation  ? 

TEMPERATURE. 

1.  Provide  a  small  vessel  of  water  and  a  thermometer. 
The  water  should  have  a  temperature  of    50°  or  60°. 
Hold  the  fingers  in  this  till  familiar  with  the  sensation. 
Place  the  thermometer  in  the  vessel  and  note  the  temper- 
ature. 

2.  Apply  heat  until  twenty  degrees  hotter,  and  again 
let  the  pupils  test  with  the  fingers  and  then  measure  with 
the  thermometer.     In  this  way,  test  with  the  hand  and 
measure  with  the  thermometer  until  the  fingers  can  be 
held  in  it  but  a  few  seconds  only. 

3.  Begin  again  with  the  temperature  first  taken  and  by 
adding  snow  or  ice  reduce  to  the  freezing  point,  testing 
with  the  fingers  and  reading  the  thermometer  as  before. 

4.  Repeat  these  experiments,  changing  the  temperature 
ten  degrees  each  time  instead  of  twenty. 

5.  After  holding  the  fingers  a  short  time  in  ice  water, 
dip  them  in  water  having  the  temperature  at  which  you 
began  ;  does  it  feel  warmer  or  cooler  than  before  ?     The 
pupil  should  test  with  his  fingers  and  express  his  judg- 
ment as  to  the  temperature  in  each  case  before  using  the 
thermometer. 

6.  Why  is  testing  the  temperature  in  this  way  with  the 
fingers  likely  to  be  untrustworthy  ? 

7.  Note  the  temperature  of  the  school-room  ;  it  should 
be  about  68°.     Compare  with  that  of  a  hall-way.     Daily 
practice  should  be  given  in  judging  the  temperature  of 

the  room. 

EXPANSION. 

i.  Fasten  one  end  of  a  small  iron  rod  or  wire,  a  foot 
long,  tightly  in  a  small  support  of  some  kind.     Against 


112  NATURE  STUDY.  [November 

the  free  end  arrange  an  index  finger  in  such  a  way  that 
it  will  move  over  a  dial.  The  index  should  be  several 
inches  long  and  the  wire  should  rest  against  it  near  the 
pivot. 

2.  Apply  heat  to  the  rod  throughout  its  length  ;  note 
the  movement  of  the  index.     What  does  its  movement 
indicate  ? 

3.  Withdraw  the  heat ;  does  the  rod  still  rest  against 
the  index  ? 

4.  Substitute  a  brass  rod  for  the  one  of  iron  and  note 
the  movement  of  the  index. 

5.  Cut  or  punch  a  hole  in  a  piece  of  tin  large  enough 
to  just  allow  a  rod  to  pass  through  it  smoothly.     Heat 
the  rod  and  try  passing  it  through  the  hole.     What  does 
this  indicate?     Cool  the  rod  and  try  again. 

6.  Can  you  see  any  reason  why  a  blacksmith  should 
heat  the  tire  of  a  wheel  before  putting  it  on  ? 

7.  Why  is  there  a  space  between  the  ends  of  the  rails 
in  a  railroad  ? 

8.  Why  heat  the  bolts  and  rivets  used  in  putting  to- 
gether the  parts  of  iron  bridges  and  boilers  ? 

9.  Allow  each  pupil  to  fill  a  small  bottle  level  full  of 
boiling  water  which  has  been  colored  with  a  little  indigo 
or  ink.     Pass  a  glass  tube  a  few  inches  long  and  of  small 
bore,  say  one-eighth  of  an  inch,  just  through  the  cork  ; 
it  should  not  project  below  the  under  surface  of  the 
cork.      Press  the   cork  tightly  into  the  bottle  and  the 
water  will  rise  in  the  tube  ;  see  that  no  bubble  of  air  rests 
underneath  the  cork  and  that  none  are  clinging  to  the 
inside  of  the  bottle.     The  water  should  stand  in  the  tube 
so  as  to  be  visible  above  the  cork,  and  the  point  to  which 
it  rises  should  be  marked.     This  is  easily  done  by  slip- 
ping down  over  the  tube  a  small  piece  of  paper.     Set  the 


November]  PH  YSICS.  1.13 

bottle  aside  until  the  water  becomes  cold.  Does  the 
water  stand  at  the  same  height  in-  the  tube  ?  Why  ? 
Why  fill  with  boiling  water? 

10.  Place  the  bottle  when  cooled  in  a  shallow  pan  con- 
taining sand,  and  heat  gradually  over  the  alcohol  lamp. 

n.  Can  you  notice  any  movement  of  the  water  in  the 
tube  ?  Why  is  the  tube  used  ? 

12.  What  is  the  effect  of  heat  upon  the  water? 

13.  Make  a  drawing  of  the  apparatus  used  and  explain 
why  each  successive  step  is  taken  in  its  arrangement. 

14.  Using  the  same  apparatus,  place  the  bottle  in  a 
vessel  containing  snow  or  ice  mingled  with  salt.     Watch 
sharply  the  column  of  water  in  the  tube. 

15.  Compare  its  movements  with  those  when  the  bottle 
was  heated. 

1 6.  In  order  to  test  the  temperature,  one  bottle  with  a 
wide  mouth  should  be  prepared  with  the  tube  and  also  a 
thermometer  through    the   cork.     At  what    temperature 
does  the  water  begin  to  rise  in  the  tube  ?     Does  it  expand 
beyond  its  original  volume  ? 

17.  From  these  two  experiments  can  you  think  of  what 
changes  and  movements  the  water  in  a  pond  must  undergo 
in  being  frozen  ? 

1 8.  Why  does  ice  form  at  the  top  and  not  at  the  bottom 
of  a  pond  or  stream  ? 

19.  What  would  likely  be  the  result  if  the  ice  should 
begin  to  form  at  the  bottom  ? 

20.  Prepare  the  bottles  again  as  above,  but  fill  them 
only  about  half  full  of  water  and  push  the  tube  through 
the  cork  until  it  reaches  nearly  to  the  bottom. 

21.  Clasp  the  upper  part  of  the  bottle  in  the  hands  and 
watch  the  tube. 


114  NATURE   STUDY.  [November 

22.  Compare  carefully  the  conditions  of  this  experi- 
ment with  those  in  the  last.     What  essential  difference 
between  them  ? 

23.  Heat  the  bottle,  as  before,  over  a  lamp  ;  account 
for  the  result  observed. 

25.  If  possible,  procure  a  bladder  or  a  small  rubber 
bag  partially  filled  with  air  ;  warm  it  gently  and  account 
for  the  result. 

BOOKS  FOR  REFERENCE. — Humboldt  Library,  No.  120.  The 
Modern  Theory  of  Heat;  and  The  Sun  as  a  Storehouse  of  Energy. 


In  this  and  other  science  work  it  will  sometimes  be 
necessary  to  have  a  means  of  getting  a  strong  heat  without 
smoke.  If  gas  is  at  hand  it  is  best  to  procure  a  Bunsen 
burner  and  attach  it  to  a  jet  with  a  rubber  tube.  An 
alcohol  lamp,  however,  will  make  a  good  substitute.  To 
make  one  of  these,  take  a  small  bottle  and  perforate  the 
cork,  making  a  round  opening  three-eighths  of  an  inch  in 
diameter.  With  a  small  piece  of  tin  make  a  tube  an  inch 
or  two  long  that  will  tightly  fit  the  hole  through  the  cork, 
allowing  it  to  project  a  short  distance  above.  The  seam 
of  the  tube  need  not  be  soldered.  Roll  a  small  flat 
lamp  wick  tightly  and  pass  it  through  the  tube.  A  large- 
sized  thimble  may  be  used  as  a  cap  for  extinguishing  the 
flame  and  to  prevent  waste  of  alcohol  when  not  lighted. 
The  cork  should  rest  loosely  in  the  bottle  when  in  use. 
A  much  better  lamp  is  made  by  using  a  metal-capped 
tooth-powder  bottle  that  may  be  bought  of  any  druggist 
for  five  cents.  This  equals  any  alcohol  lamp  of  its  size 
that  is  made  specially  for  the  purpose,  and  it  is  much 
cheaper,  and  will  answer  all  purposes  where  heat  is  re- 
quired in  performing  the  experiments  suggested  in  this 
book. 

1.  Take  a  small    stick  of  wood  and  cut  it  into  fine 
pieces  ;  set  fire  to  another  similar  one  and  let  it  be  con- 
sumed.    Watch  closely  the  changes  taking  place. 

2.  How  has  the   wood  been  changed  in   the  first  in- 
stance ?     Are  there  any  changes  in  amount  ? 

"5 


n6  NATURE   STUDY.  [November 

3.  Has  there  been  any  change  whatever  in  the  substance 
of  the  wood  ? 

4.  What  was  the  first  change  noticed  in  the  burning 
wood?     Note  the  charring. 

5.  Does  anything  remain   after  burning   has  ceased  ? 
What  is  it  ? 

6.  Does  it  in  any  way  resemble  the  wood  ? 

7.  Is  there  in  what  remains  either  as  great  bulk  or 
weight  as  there  was  in  the  wood  ? 

8.  What  has  become  of  the  part  that  has  disappeared  ? 

9.  Allow  the  smoke  to  strike  a  piece  of  porcelain  or 
glass  ;  what  collects  on  the  surface  ? 

10.  Does  the  soot  in  any  way  resemble  the  wood  ? 

11.  Was  it  a  part  .of  the  wood  ? 

12.  Hold    the   flame   of   an  alcohol  lamp  under  and 
near  the  soot  on  the  plate  ;  what  becomes  of  it  ?     Is  it 
totally  consumed  ? 

13.  What  is  the  greatest  difference,  in  result,  of  the 
above  operation  on  wood  ? 

14.  In  the  first  instance  there  was  a  physical  change  ; 
in  the  second  a  chemical  change. 

15.  Try  lowering  the  lighted  stick  into  a  wide-mouthed 
bottle  ;  try  again  with  a  bottle  or  jar  of  larger  size  ;  com- 
pare the  burning  under  such  conditions  with  those  in  the 
first  instance. 

16.  What  conditions   seem  to   be  necessary   for   the 
burning  of  the  wood  ? 

17.  Is  the  air  in   the  bottle  changed  when  the  stick  is 
burned  in  it  ? 

18.  Pour    into  a  clean  bottle   half   an  inch  of  lime- 
water  and  shake  it  ;  does  it  change  ? 

19.  Now  burn  a  match  in  the  bottle  and  shake  again  ; 
is  the  lime-water  changed  ? 


November]  CHEMISTRY.  -  117 

20.  Does  this  recall  the   results  of  any  experiment  of 
a  previous  month  ? 

21.  Drop  apiece  of  marble  into  a  small  bottle  of  strong 
vinegar  or  into  water  mixed  with  hydrochloric  acid  ;  how 
does  the  action  differ  from  what  takes  place  when  it  is 
put  into  water  ?     (See  Chemistry  for  October.) 

22.  Use  a  piece  of  limestone  in  place  of  the  marble  ; 
describe  closely  what  occurs. 

23.  What  do  the  bubbles  contain  ?     Lower  a  lighted 
match  into  the  bottle. 

24.  By  means  of  a  bent  tube  through  the  cork,  draw 
some  of  the  gas  formed  out  into  a  small  amount  of  lime- 
water  ;  do  the  results  with  the  lime-water  and  match  re- 
call any  previous  experiments  ?     This  is  a  test  for  car- 
bon dioxide  gas. 

25.  What  tests  proved  it  to  be  different  from  air  ?     In 
what  respects  is  it  like  air  ? 

26.  Place  in  a  Florence  flask  or  pint  bottle  a  handful 
of  pieces  of    marble,  cover  them  with    water   and    add 
hydrochloric  acid  till  gas  comes  off  freely.     Through  a 
bent  glass  tube  in  the  cork  convey  the  gas  to  the  bottom 
of  another  wide-mouthed  bottle  or  a  beaker. 

27.  After  a  few  minutes,  with  a  movement  as  of  pour- 
ing, invert  the  beaker  over  a  burning  taper  or  match  ? 
How  do  you  account  for  the  result  ? 

28.  Why  is  it  possible  to  collect  this  gas  in  an  open 
beaker  as  we  did  ?     Why  is  it  possible  to  pour  it  like 
water  ? 

29.  When  the  bubbling  ceases,  pour  off  the  liquid  and 
dry  the  solid  that  remains  ;  does  it  differ  from  what  was 
used  originally  ? 

30.  Will  acid  act  upon  it  again  as  it  did  at  first  ? 


Il8  NATURE    STUDY.  [November 

31.  Try  the  vinegar  with  chalk  or  limestone  or  mar- 
ble that  has  been  mixed  with  water. 

32.  Have  the  substances    in    the   above   experiments 
undergone  physical  or  chemical  change  ? 

33.  Take     a    small     amount    of     sulphur    and    mix 
thoroughly  with  about  the  same  quantity  of  iron  filings  ; 
can  you  distinguish  the  two  substances  in  the  mixture  ? 

34.  Can  you  separate  the  two  substances  ?     Blow  upon 
the  heap. 

35.  Pass  a  magnet  back  and  forth  near  the  mixture  ; 
what  is  the  result  ? 

36.  Make  another  similar  mixture  of  sulphur  and  fil- 
ings in  a  cup  ;  warm  gradually  over  the  burner. 

37.  Watch  closely  and  describe  the  changes  that  take 
place  ? 

38.  After  the  action   ceases,  examine    the  substance 
formed  and  compare  with  the  original  materials. 

39.  Can  you   distinguish  the  sulphur?     How   does  it 
differ  from  the  filings  ?     The  new  substance  thus  formed 
is  called  iron  sulphide.     Instead  of  writing  the  word  iron 
in  full,  the  symbol  Fe  is  generally  used,  and  instead   of 
the  word  sulphur  the  symbol  S  is  written.     Iron  sulphide 
has  for  its  symbol,  Fe  S.     In  the  first  instance  the  iron 
and  sulphur  formed  merely  a  mixture  ;  in  the  second  a 
combination.     What  is  the  difference  ? 

40.  Which  experiment  with   the  filings    and   sulphur 
more  closely  resembles  that  with  the  acid  and  marble  ? 

41.  In  what  important  particular  are  they  different  ? 

42.  In  how  many  of  the  experiments  performed  could 
you  distinguish  new  substances  that  were  formed  ? 

43.  What  were  the  tests  used  which  proved  their  pres- 
ence ? 


November]  CHEMIS  TRY.  1 1 9 

44.  How  does  the  new  substance  which  was  formed  in 
the  bubbles  of  vinegar  differ  from  the  Fe  S  in  the  last  ex- 
periment ? 

BOOKS  FOR  REFERENCE.  Remsen's  Introduction  to  the  Study  of 
Chemistry. 


1.  How  does  the  mean  temperature  for  the  first  week 
compare  with  that  of  the  first  week  in  October  ?     What 
causes  the  difference  ? 

2.  Is  the  direction  of  the  prevailing  wind  the  same 
as  it  was  for  October  ?     Is  it  a  cold  or  a  warm  wind  ? 

3.  How  can  you  account  for  its  direction  ? 

4.  What  wind  is  accompanied  by  a  clear  sky  ?     How 
does  this  wind  affect  the  temperature  ? 

5.  What  wind  has  accompanied  the  rains?     Are   the 
rains  more  or  less  frequent  than  they  were  in  the  preced- 
ing months? 

6.  How  does  the  amount  of  rainfall  compare  with  that 
of  the  preceding  months  ? 

7.  What  is  the  most  common  form  of  cloud  observed  ? 

8.  How  have  they  changed  in  character  ?     Are  they 
higher  or  lower  than  they  were  in  September  ? 

9.  Which  is  the  more  common  this  month,  frost  or 
dew  ? 

10.  What  is  the  character  of  a  night  preceding  a  frost  ? 

11.  Does  the  frost  form  upon  all  objects  outdoors  ? 

12.  How  does  a  windy  night  affect  the  formation  of 
frost  ?     A  cloudy  night  ? 

13.  Examine  some  frost  crystals  under  a  lens. 

14.  Are  they  uniform  in  shape  and  size  ?     Are  frost 
crystals  frozen  drops  of  dew  ? 

15.  What  difference  is  therebetween  the  conditions  for 
forming  dew  and  those  for  forming  frost  ?     In  what  re- 
spects are  they  the  same  ? 


November]  METEOROLOGY.  12 1 

16.  Has  the  barometer  in  any  way  indicated  the  change 
noted  in  the  weather  ? 

17.  What  was  the  mean  height  of  the  barometer  on  the 
clear  days  ? 

1 8.  What  was  its  mean  height  on  the  rainy  or  stormy 
days  ? 

19.  In  what  month  has  the  barometer  shown  the  great- 
est range  of  movement  ?     In  which  the  least  ? 

20.  In  what  month  has  there  been  the  greatest  fluctua- 
tion in  the  weather  ?     In  what  month  the  least  ? 

21.  Is  there  any  uniformity  in  the  temperature  which 
accompanies  a  falling  barometer  ?     Is  it  the  same  or  dif- 
ferent with  a  rising  barometer  ? 

STUDY  OF  THE  WEATHER   BUREAU   MAPS. 

22.  Do   the  isotherms  vary  more  or  less  this  month 
from  their  general  direction  than  they  did  last  month  ? 

23.  Where  is  the  variation  greatest  ?     What  cause  can 
you  assign  ? 

24.  In  what  part  of  the  country  has  there  been  the 
heaviest  rainfall  ? 

25.  Where  has  there  been  the  most  snow  ? 

26.  Where  is  the  region  of  lowest  temperature  ? 

27.  Have   the   mountains   the   same   effect   upon   the 
isotherms  that  they  had  in  September  ? 

28.  Do  the  coast  lines  exert  the  same  influence  upon 
the  isotherms  as  last  month  ? 

29.  What  was  the  lowest  isotherm  that  passed  through 
this  locality  during  the  month  ? 

30.  What  was  the  lowest  latitude  of  that  isotherm  in 
September?     In  October? 

31.  What  inference  may  be  derived  from  its  varying 
position  ? 


Hetronom^ 

The  facts  that  have  been  noted  from  time  to  time  as  to 
the  variation  in  the  length  of  day  and  night,  the  change 
of  season,  the  changing  shadow,  the  different  position  of 
the  rising  and  setting  sun  on  the  horizon,  should  all  be 
used  in  giving  the  pupils  a  clearer  idea  of  the  earth  and 
the  sun  in  their  relative  positions,  and  also  broader  con- 
ceptions of  these  bodies  themselves.  To  accomplish  the 
latter  end,  the  pupils  should  be  trained  to  think  of  the 
earth  and  the  sun  without  the  use  of  the  globe  for  illus- 
tration. Make  the  same  use  of  the  symbol  in  this  case  as 
in  all  others  ;  use  it  only  as  an  aid  to  the  conception  of 
the  object,  but  do  not  let  it  entirely  take  the  place  of  the 
object,  inasmuch  as  then  the  pupil's  conception  must  be 
of  the  symbol  only. 

1.  Compare    the   length  of  day  and   night  with   that 
of  preceding  months. 

2.  Is  the  rate  of  variation  each  day  the  same  during 
the  month  ?     How  does  it  differ  from  that  of  October 
and  September  ? 

3.  In    what   direction    is   the    noon-mark    changing  ? 
Why? 

4.  Is  it  changing  more  or  less  rapidly  than  it  did  in  the 
preceding  months? 

5.  Are  the  facts  observed  thus  far  sufficient  to  prove 
the  revolution  of  the  earth  around  the  sun  ? 

6.  What  other  supposition  can  you  make  that  would 
account  for  the  phenomena  observed  ? 


November]  ASTRONOMY.  123 

7.  Use  a  globe,  if  necessary,  to  illustrate  your  meaning. 

8.  Has  the  diminishing  day  had  anything  to  do  with 
the  changing  season  ? 

9.  Show  to  what  other  cause  the  change  in  season  is 
due. 

10.  What  time  elapses  between  two  new  moons? 

11.  Show  what  the  position  of  the  moon  must  be  with 
respect  to  the  earth  and  sun  when  it  is  new.     Why  is  it 
crescent  shaped  ? 

12.  In  what  direction  do  the  horns  point?     Why  do 
they  point  in  this  direction  ?     Does  the  direction  vary  ? 
Why? 

13.  Does  the  moon  always  follow  the  same  path  across 
the  sky  ? 

14.  Where   does  the   new  moon  always  appear  first  ? 
Why? 

15.  Where  is  it  when  between  old  and  new  ? 

16.  The  constellations  to  be  observed  are  the  same  as 
those  for  October. 

BOOKS  FOR  REFERENCE.     Astronomy  Science  Primer,  by  Lockyer. 
Newcomb's  Astronomy,  Briefer  Coarse.     See  previous  months. 


(Beograpb^ 


CLIMATE   OF  NORTH  AMERICA. 

By  a  judicious  reference  to  the  Signal  Service  Maps, 
and  to  maps  of  the  continent,  upon  which  are  marked 
the  isotherms,  a  detailed  study  of  the  climate  of  North 
America  may  proceed  from  month  to  month.  It  must 
not  be  expected  that  the  pupils  will  generalize  sufficiently 
to  be  able  to  see  all  the  laws  underlying  the  distribution 
of  heat  and  moisture  ;  yet  such  use  of  the  maps  will 
assist  them  to  collect  in  a  practical  way  a  large  number 
of  the  facts  upon  which  the  laws  are  based,  and  which 
open  the  way  for  a  clear  understanding  of  the  laws 
further  along.  The  data  gathered  from  the  study  of 
physical  maps  should  be  used  to  supplement  and  extend 
the  knowledge  and  experience  they  have  gained  from 
their  own  observations  recorded  in  the  Meteorological 
Record. 

1.  What  regions  of  the  United  States  show  the  greatest 
contrasts  as  to  rainfall  during  the  month  ? 

2.  Note  the  latitude  of  the  two  regions  ;  also  the  ele- 
vation, the  winds  which  traverse  them,  and  their  nearness 
to  the  sea. 

3.  Can  you  tell  what  conditions  have  most  affected  the 
rainfall  ? 

4.  Which  condition  has  the  most  to  do  with  the  tem- 
perature of  the  two  regions  ? 


November]  GEOGRAPHY.  125 

5.  What  difference  is  noted  in  the  temperature  of  the 
two  places  ? 

6.  Contrast  the  character  of  the  prevailing  winds  upon 
the  Pacific  slope  with  those  upon  the  Atlantic.     How  do 
the  two  regions  differ  in  temperature  in  the  same  lati- 
tude ? 

7.  Is  the  difference  in  temperature  dependent  upon  the 
winds  ?     Note   the   direction  from  which  they  come  in 
each  case. 

8.  Compare  the  rainfall  of  the  interior  between  the  two 
great  mountain  systems  with  that  on  the  coasts.     What  is 
the  direction  of  the  prevailing  wind  in  the  interior  ? 

9.  Compare  the  rainfall  in  the  northern  and  southern 
regions  of  the  interior.     Upon  what  does  the  difference 
depend  ? 

10.  How  can  you  account  for  the  difference  in  tem- 
perature of  the  northern  and  southern  divisions  of  the 
interior  ? 

IT.  What  contrasts  in    temperature  and   rainfall    are 
noted  between  the  mountainous  parts  and  the  lowlands? 

12.  What  contrasts,  that  you  know  of,  between  the  peo- 
ple of  different  regions  are  due  to  difference  in  climate  ? 

13.  Are  any  differences  that    may  exist  between  the 
people  on  the  Pacific  coast  and  the  Atlantic  coast  due 
to  difference    in  climate  ?     Are  the  differences  as   well 
marked  as  they  are  between  the  North  and   the   South  ? 
Why? 

14.  Contrast  the  people  of  the  far  north  with  those  of 
the  extreme  south,  as  to  character,  habits,   occupation, 
etc.     How  does  the  climate  affect  them  ? 

15.  How  does  difference  of  climate  affect  the  produc- 
tions in  our  latitude  ? 

16.  Where  are  there  the  greatest  contrasts  in  the  pro- 


126  NATURE    STUDY.  [November 

ductions  in  the  same  latitude  ?     Are  these  due  to  climatic 
differences  ? 

17.  Compare  the  rainfall  for   the  month  of  the  region 
just  east  of  the  Rocky   Mountains  with  the  region  just 
west  of  the  Appalachian  Mountains  ;  how  do  you  account 
for  the  difference  ? 

1 8.  Where  do  the  winds  that  sweep  the  two  regions 
come  from  ? 

DRAINAGE  OF  SOUTH  AMERICA. 

1.  Note,  by  the   examination  of  a  good  map  of  South 
America,  the  ocean  which   receives   the  greatest  part  of 
the  drainage  waters ;  compare  in  this  respect  with  North 
America. 

2.  From  the  flow  of  the    rivers,  how  can  you  tell  the 
location  of  the  continental  slopes  ?     Bound  the  slopes. 

3.  Where  is  the  great  continental  water-parting? 

4.  How  does  it  compare  in   relative  position  with  the 
great  continental  water-parting  of  North  America  ?     How 
does  it  compare  in  direction  ? 

5  What  resemblance  in  the  two  continents  as  to  their 
great  slopes  ?  Compare  the  two  Pacific  slopes.  The 
Atlantic  slopes. 

6.  Do  the  rivers  in  the  north  of  each  continent  indicate 
any  similarity  in  the  slopes  in  these  regions  ? 

7.  What   minor  water-partings  are    indicated    by  the 
rivers  of  the  eastern  slopes  ? 

8.  How  does  the  position  of  the  minor  water-partings 
differ   from  those  of  North    America  ?     How    do    they 
compare  in  direction  ? 

9.  Compare  the  slopes  of  the   interior  with  those  of 
North  America. 

10.  In  what  directions  does  the  interior  slope  ? 


November]  GEOGRAPHY.  127 

1 1.  What  resemblance  and  difference  can  be  discovered 
in  the  great  river  systems  of  the  two  continents? 

12.  What  differences  as  to  their  minor  river  systems  ? 

13.  What  part  of  the  continent  must  receive  the  great- 
est rainfall  ? 

14.  Compare  the  northern  and  the  southern  parts  as  to 
rainfall,  basing   the    comparison    upon   the  size  of   the 
rivers. 

15.  Compare  the  regions  as  to  rainfall  with  correspond- 
ing  parts   of  North  America  ;  what   difference   noted  ? 
Why? 

1 6.  What  inference,  based  upon  the  great  rivers,  can 
you  make  respecting  the  fertility  of  different  regions  of 
the  eastern  slope  ?     What  inference  in  this  respect  about 
the  western  slope  ? 

17.  Where  is  the  greatest  river  basin  ?     What  are  its 
boundaries  ?     The  second,  and  third  in  size  ? 

18.  How    does  the  general    slope  of  these  basins  as 
wholes  differ  ? 

19.  Compare  the  Brazilian    Highland  with   the  Appa- 
lachian. 

20.  In  what  latitude  are  the  greatest  rivers?     In  what 
latitude  are  the  smallest  rivers  ?     Compare  with    North 
America. 


(Beolog?. 


PEBBLES. 

Have  each  pupil  take  the  entire  collection  of  pebbles 
gathered  during  the  preceding  months  and  assort  them 
with  respect  to  their  different  characteristics,  such  as 
shape,  color,  material,  etc.,  and  by  a  careful  considera- 
tion learn  something  of  their  history.  This  work  should 
be  preceded  by  as  much  actual  field  work  as  possible.  No 
teacher  ought  to  hesitate  to  begin  such  field  work,  simply 
because  of  a  lack  of  experience.  It  is  the  want  of  actual 
contact  with  things  that  renders  so  much  teaching  un- 
satisfactory to  the  teacher  and  obscure  to  the  pupils. 
Visit  some  stream  and  spend  a  few  hours  studying  the 
pebbles  that  line  its  banks.  No  matter  how  insignificant 
the  brook  may  be,  it  will  hardly  fail  to  afford  abundant 
illustration  of  the  force  of  water  in  pebble-making.  For- 
tunate indeed  is  the  teacher  who  can  also  visit,  with  his 
classes,  the  shore  of  a  lake  or  the  sea,  and  there  study 
the  same  force  at  work  under  different  conditions.  The 
wind  here  plays  a  part  equally  important  with  the  water, 
and  the  two  together,  through  the  ceaseless  rolling  waves, 
are  as  destructive  as  the  swiftest  current.  The  mobile 
water  curling  in  graceful  breakers  and  spreading  itself 
out  in  thin  layers  on  the  beach,  seems  to  possess  but 
little  of  the  force  necessary  to  accomplish  the  results 
wrought  out  along  every  shore.  But  a  cupful  of  water 


November]  GEOLOGY.  129 

taken  from  one  of  these  waves  will  show  that  it  carries  a 
multitude  of  sand  grains  that  rasp  each  other  and  the 
shore  continually.  In  the  larger  waves,  great  quantities 
of  pebbles  are  constantly  rolled  in  and  out  with  the  ad- 
vancing and  retreating  waters,  and  the  grinding,  grating 
sound  accompanying  the  alternate  movements  tell  some- 
thing of  the  great  work  that  is  going  on.  In  times  of 
tempest,  the  force  is  increased  a  thousand  fold.  With  a 
thundering  roar,  the  water,  laden  with  great  bowlders, 
hurls  itself  in  some  places  against  the  shore  with  a  force 
sufficient  to  demolish  the  most  substantial  works  of  man  ; 
elsewhere,  it  rolls  up  immense  heaps  of  sand,  gravel,  and 
stones,  and  leaves  them  perhaps  hundreds  of  miles  from 
the  starting  point  of  their  journey.  If  in  addition  to  these 
illustrations  it  is  possible  to  study  and  compare  with  them 
the  action  of  the  glaciers,  the  interest  will  be  greatly 
increased. 

The  different  forms  of  the  glacial  pebbles,  the  different 
manner  in  which  they  are  deposited,  the  means  by  which 
they  were  carried,  will  all  furnish  rich  material  for  care- 
ful thought  and  study.  It  is  an  excellent  exercise  for 
the  reasoning  powers  to  trace  the  history  of  a  pebble 
from  its  present  condition  and  surroundings,  back 
through  its  various  stages  to  its  origin  in  some  distant 
cliff  in  a  remote  age.  How  much  of  this  history  can  be 
written,  will  depend  upon  the  age  and  experience  of  the 
pupils  ;  some  will  perhaps  read  its  history  only  to  water 
which  rolled  it  and  made  it  round  ;  others  will  follow  it 
to  a  particular  lake  or  stream,  and  still  others  may  see 
its  footsteps  leading  to  some  cliff.  It  little  matters  how 
far  they  go,  or  how  far  short  of  the  end  they  may  have 
to  stop,  if  in  accounting  for  them  they  learn  to  properly 
use  and  interpret  the  conditions  under  which  the  pebbles 


!3°  NATURE    STUDY.  [November 

are  found.  It  is  not  enough  for  a  full  conception  that 
they  follow  merely  the  footsteps  of  the  pebbles  through 
space  ;  the  element  of  time  is  one  of  greatest  importance, 
but  it  is  a  factor  that  can  never  be  anything  but  vague 
in  the  minds  of  the  most  highly  trained,  and  too  much 
must  not  therefore  be  expected  of  young  pupils.  No 
effort  should  be  spared,  however,  to  broaden  their  ideas 
in  this  direction,  inasmuch  as  a  lack  of  this  conception 
stands  in  the  way  of  many  people  who  cannot  receive 
the  modern  theory  of  the  earth's  development. 

Whether  all  or  but  one  of  the  above  illustrations  of 
the  results  of  water  action  are  at  the  command  of  the 
teacher,  let  it  once  more  be  urged  that  the  means  at 
hand  be  used.  It  is  the  universal  experience  that  not 
only  do  the  facts  so  learned  remain  longer  in  the  mind, 
but  that  such  lessons  often  prove  to  be  initiative  of  a 
line  of  observation  and  thought  that  lasts  through 
life. 

1.  Where  were  the  pebbles  in  your  collection  found  ? 

2.  Can  you   distinguish  those  that  were  found  on  the 
banks  of  a  stream   from  those   found   on  the  shore  of  a 
lake  ? 

3.  What  have  you   observed  in   the    arrangement   of 
pebbles  on  the  river  bank  or  lake   shore  ?     Is  it  exactly 
the  same  in  both  cases  ? 

4.  Have  you  found  pebbles  in  any  considerable  quan- 
tity at  a  distance  from   water  ?     Does  the  water  reach 
the  place  in  times  of  floods  ? 

5.  How  can  you  account  for  this  remoteness  of  pebbles 
from  water?     Are  they  like  the  rocks  found  in  the  quar- 
ries in  the  vicinity  ? 

6.  Can  you  tell  whether  they  were  deposited  by  run- 
ning or  still  water  ? 


November]  GEOLOGY.  I31 

7.  Can    you  tell    whether    the   water    was    shallow  or 
deep  ? 

8.  Were  they  deposited  on  a  shore  or  in  the  middle  of 
a  lake  or  stream  ? 

9.  Are  there  any  other  evidences  of  water  action  near 
by? 

10.  Can  you  form  any  estimate  as  to  the  length  of  time 
since  they  were  deposited  ? 

n.  What  things  on  the  surface  will   assist  in  giving 
some  idea  of  the  time  ? 

12.  Are  there  any  large  trees  in  the  vicinity?     What 
is  the  depth  of  the    vegetable  mold  ?     Is  the    sod  well 
formed  ? 

13.  Which  gives  the  best  evidence  of  the   length  of 
time  since  the  pebbles   were  deposited,  the   trees,   the 
vegetable  mold,  or  the  sod  ? 

14.  What  is  the  nature  of  the  ground  with  which  they 
are  mingled,  sandy,  clayey,  or  loamy  ? 

15.  How  does  the  surface  of  a  pebble  differ  from  that 
of  a  freshly  broken  stone  ? 

16.  How  does  it  differ  from  one  that  has  been  exposed 
to  the  air  for  a  long  time  ? 

17.  What  makes  this  difference  in  surface  ? 

18.  Assort  the  pebbles  with  respect  to  shape  ;  what  is 
the  most  common  form  ? 

19.  Why  should  they  be  rounded  ?     Upon  what  does 
the  shape  appear  to  depend  ? 

20.  Is  it  the  hardness  of  the  material  in  the  pebbles 
or  its  arrangement  that  does  the  more  to  determine  their 
shape  ? 

21.  Assort  and  rearrange  the  pebbles  again  with  re- 
spect to  the  material  composing  them  ;  compare  as  to 
color,  hardness,  etc. 


I32  NATURE   STUDY.  [November 

22.  Can  you  tell  how  it  is  that  many  different  kinds 
are  found  together  ? 

23.  Does  any  one  kind  of  material  prevail  to  any  great 
extent  more  than  the  others  ? 

24.  Is  any  of  the  rock  composing  the  pebbles  to  be 
found  in  neighboring  quarries  ? 

25.  Can  you  recall  whether  or  not  the  ledges  that  may 
usually  be  seen  projecting  from  a  cliff  or  hillside  are  of 
the  same  kind  of  rock  ? 

26.  What  evidence  have  you  seen  that  such  cliffs  are 
wearing  away  ? 

27.  A  great  variety  of  rock  may  be  picked  up  by  a 
stream  traversing  many  miles  of  country,  but  how  is  this 
variety  possible  with  a  lake  ? 

28.  How  does  the  force  which  rounds  off  the  pebbles 
in  a  stream  differ  from  that  in  a  lake  or  on  the  seashore  ? 

29;  What  part  does  the  water  really  play  in  both  cases  ? 

30.  Can  you  think  of  any  conditions  which  affect  the 
rate  at  which  pebbles  will  be  transported  ?     Is  this  course 
a  direct  one  to  the  mouth  of  the  stream  ? 

31.  Under   what   conditions    will    they   be   deposited 
along  the  banks? 

32.  Under  what  circumstaces  will  they  be  dropped  in 
mid-stream  ?     When  will  such  be  moved  again  ? 

33.  Upon  what  conditions  will  those  along  the  bank 
be  allowed  to  remain  ? 

34.  Is  it  likely  that  pebbles  left  in  sand  on  the  build- 
ing bank  of  a  river  will  be  again  disturbed  ? 

BOOKS  FOR  REFERENCE.    See  September.    Also  Humboldt  Library, 
No.  38.     Chapter  i. 


An  interesting  variation  in  the  study  of  this  subject 
this  month  will  be  found  in  a  consideration  of  common 
mineral  fuel. 

The  pupils  should  supply  themselves,  as  far  as  possible, 
with  specimens  of  bituminous,  anthracite,  cannel,  and 
splint  or  block  coals  ;  also,  with  examples  of  peat  and 
coke.  A  good  specimen  of  lignite  is  likewise  needed  to 
complete  the  list. 

Compare  the  different  specimens  as  to  weight.  Which 
is  the  heaviest  ?  The  lightest  ? 

1.  The  weight  of  a  solid  or  liquid  compared  with  an 
equal  bulk  of  water  is  called   its  specific  gravity.     To 
find  the  specific  gravity  of  a  solid,  weigh  it  first  carefully 
on  an  ordinary  balance  ;  then   suspend   it  from  one  of 
the  scale  pans  by  means  of  a  fine  thread,  and  immerse 
it  entirely  in  a  small  vessel  of  water,  and  obtain  its  weight 
submerged.     The  weight  in  air  divided  by  the  loss  of 
weight  in  water  is  the  specific  gravity. 

2.  Which  specimen  has  the  greatest  specific  gravity  ? 
which  the  least  ?      Do  you  notice  any  correspondence 
between  the  specific  gravity  and  the  hardness  ? 

3.  What  difference  in  luster  do  you  notice  ?     Are  they 
sufficiently  well  marked  to  enable  one  to  distinguish  the' 
different  kinds  of  coal  ?     Some  kinds  show  a  play  of 

,  different  colors,  and  are  known  as  peacock  coal. 

4.  How  do  they  differ  in    hardness?     If  you  have 

133 


134  NATURE    STUDY.  [November 

different  varieties  of  the  same  kind,  i.  e.,  specimens  from 
different  mines,  can  you  notice  differences  in  them  ? 

5.  Try  with  a  lighted  match  to  set  fire  to  the  different 
specimens,  selecting  sharp  edges  or  corners  for  the  pur- 
pose.    Which    one   burns   easiest  ?      Which    with    most 
difficulty  ? 

6.  Note  the  odor  of  the  burning  substance  in   each 
case  ;  how  does  the  peat  differ  from  the  rest  ? 

7.  What  difference  in  the  ways  of  burning  in  grates  and 
stoves  ? 

8.  Compare  the  coke  with  the  different  coals.     It  is 
the  carbon  left  after  burning  the  coal  to  rid  it  of  other 
substances   in   its  composition.     It   is   used  in   smelting 
iron.     (See  Mineralogy  for  December.) 

9.  All  the  coals,  and   peat  included,  originate  in  the 
same  way,  but  each  different  kind  represents  a  different 
stage  in  formation.     It  is  the  result  of  immense  beds  of 
vegetable  material  becoming  deeply  covered  in  succeed- 
ing ages  by  the  rock  and  earth  now  found  above  the  coal 
seams.     Peat  is  coal  in   its  earliest  stage  of  formation, 
and  anthracite  is  coal  in  its  latest  and  completed  stage. 
It  has  been  changed  from  the  bituminous  variety,  to  that 
of  its  present  character,  by  means  of  heat  and  pressure. 

10.  Examine  a  piece  of  the  "  lead  "  of  a  pencil  ;  this 
substance  is  called  graphite   and   is  pure  carbon.     It  is 
also  known  as  plumbago. 

n.  If  possible,  get  a  piece  of  native  graphite  ;  note 
its  luster  and  peculiar  feel. 

12.  What  other  use  has  this  mineral  besides  that  in 
.the  manufacture  of  lead-pencils  ? 

REFERENCE.     Read  Applied  Geology,  by  S.  G.  Williams. 


Zoology 


GENERAL  OBSERVATIONS. 

1.  Can  any  of  the  summer  birds  be  found?     If  so, 
where  do  they  stay  ? 

2.  Have    you    found    any    newcomers  ?      Have    they 
come  from  the   north  or  south  ?     What  is  their  food  ? 
Do  they  sing?     Are  they  building  nests  ? 

3.  Is  there  any  insect  life  abroad  ?     Watch  sharply  on 
warm  days  and  in  sheltered  places. 

4.  Hunt  for  earthworms.     How  deep  do  they  burrow 
in  winter  ? 

5.  In  what  condition  do  the  fish  spend  the  winter? 
The  craw-fish  ?     Frogs  ? 

6.  Look  for  these  under  leaves  and  in  mud  along  the 
sides  and  in  the  bottom  of  ponds. 

7.  Do  tadpoles  live  over  winter  ? 

ANIMAL  MOVEMENTS. 

The  following  studies  should  be  based  upon  what  the 
pupils  have  been  able  to  observe  about  their  own  move- 
ments, as  well  as  those  of  the  common  domesticated  ani- 
mals. Ample  opportunity  should  be  given  beforehand 
for  the  observations  to  be  made,  and  the  discussion 
should  not  be  carried  beyond  the  limits  set  by  those  ob- 
servations. By  this,  it  is  not  intended  to  circumscribe 
too  closely  any  legitimate  reasoning  that  the  pupils  may 

'35 


*36  NATURE   STUDY.  [December 

attempt,  but  merely  to  guard  against  the  really  vicious 
habit  that  some  pupils  have,  in  the  beginning,  of  setting 
up  some  theory  independent  of  any  actual  observation, 
and  trying  to  defend  it  by  vague  speculations.  That 
rapid  progress  may  be  made,  pupils  should  be  encouraged 
to  be  candid  and  to  be  ready  to  give  up  promptly  any 
theory  or  supposition  as  soon  as  it  can  be  shown  to  be 
inconsistent  with  the  facts  of  observation. 

1.  Why  is  it  necessary  for  most  animals  to  move  from 
place  to  place  ?     Such  animals  are  said  to  have  the  power 
of  locomotion. 

2.  Do  you   know  of  any  animals  that  cannot  move 
about  ?     How  do  they  get  their  food  ?     How  are  they 
protected  from  their  enemies  ? 

If  possible,  secure  specimens  of  coral,  sponges,  and 
oysters  in  the  shell.  The  points  of  attachment  may  easily 
be  discovered  and  something  of  their  modes  of  life  may 
be  learned. 

3.  How  does  the  power  of  flight  affect  the  life  and 
habits   of    birds  ?      Consider   the   advantages   in    food- 
getting,  and  in  means  of  escape  and  attack,  that  are  due 
to  flight. 

4.  How  has  it  affected  their  distribution  ?     What  bar- 
riers are  difficult  for  birds  to  overcome  ? 

5.  Make  a  study  of  the  way  different  animals  walk  ; 
first  examine  those  that  walk  on  four  legs,  as  the  cat, 
dog,  horse,  cow,  rabbit,  squirrel,  and  any  others  that  can 
be  seen. 

6.  Contrast  the  cat  and   dog  ;   what  is  the  order  in 
which  they  place  their  feet  in  taking  a  step  ? 

7.  Note  the  motions  of  the  trunk  of  each  as  they  step  ; 
what  difference  do  you  notice? 

8.  What  gives  the  cat  its  stealthy  tread  ?     Its  velvety 


December]  ZOOLOGY.  137 

paws  contribute  partly  to  it,  but  they  are  not  the  only 
cause.  Notice  as  the  cat  steps  how  the  body  sinks 
slightly  at  the  joints  where  the  fore-limbs  are  hinged  to 
the  body  at  the  elbow,  and  that  the  same  is  noticeable  in 
the  hind  limbs  at  the  heel  joint,  though  somewhat  less  in 
amount.  These  movements,  due  to  the  great  flexibility 
of  the  joints  in  the  foot,  and  to  the  fact  that  when  the 
fore-paw  is  put  to  the  ground  the  leg  is  not  vertically 
under  the  body  but  obliquely  forward,  give  a  spring  to 
the  step  that  is  wanting  in  all  other  classes  of  quadrupeds. 

9.  Compare  the  movements  of  the  cat  with  those  of 
the  dog  ;  what  reason  can  you  think  of  for  the  difference 
in  their  gait  ? 

10.  What  habit  or  need  of  these  animals  has  done  most 
to  fix  their  gait  ? 

11.  Compare  the  movement  of  the  horse  and  the  cow  ; 
in  what  order  do  they  place  their  feet  in  walking  ? 

12.  In  what  order  are  the  horse's  feet  placed  in  trot- 
ting ?     What  is  the  order  in  pacing  or  the  rack  ?     In 
galloping? 

13.  Does  a  cow  trot  ?    How  does  the  movement  of  the 
hind  legs  differ  from  that  of  the  horse  ? 

14.  Can  you  see  wherein  lies  the  greater  capacity  of 
the  horse  for  speed  ? 

15.  How  does  the  locomotion  of  the  rabbit  differ  from 
that  of  the  cat  and  dog?    What  is  the  order  in  which  the 
rabbit  moves  his  legs  ? 

16.  How  do  the  rabbit  and  the  cat  differ  in  making  a 
spring  ? 

17.  What  is  there  in  the  life  of  the  rabbit  that  makes 
him  draw  his  hind  legs  under  him  in  a  crouching  atti- 
tude? 

18.  In  which  are  the  hind  quarters,  compared  with  the 


I38  NATURE    STUDY.  [December 

fore  quarters,  the  more  developed,  the  rabbit  or  the  cat  ? 
Compare  both  of  them  with  the  dog. 

19.  How  do  the  movements  of  the  squirrel's  legs  differ 
from  those  of  the  rabbit's  ? 

20.  Which  of  the  animals  studied   does   the    squirrel 
resemble  most  in  locomotion  ? 

21.  Compare  the  development  of  its   different  parts 
with  that  of  the  rabbit,  dog,  and  cat  ;  which  does  it  most 
closely  resemble  ? 

22.  In  what  kinds  of  places  do  these  animals  live  in 
their  wild  state  ?     How  are  their  movements  fitted  for 
such  places  ? 

23.  In  animals  that  walk  on  two  legs,  to  what  uses  are 
the  other  pair  of  limbs  devoted  ? 

24.  How  does  the  movement  upon  two  limbs  affect  the 
position  of  the  body?     Why  is  the  position  of  the  bird 
less  upright  than  that  of  man  ? 

25.  What  are  the  advantages  of  the  upright  position  for 
man  ? 

26.  Is  there  any  advantage  in  turning  the  toes  out  in 
walking  ?     What  joint  permits  of  this  turning  of  the  toes 
outward  ? 

27.  Which  is  the  easier  mode  of  walking,  with  the  feet 
parallel,  or  diverging  outward  at  the  toes  ?     Which  is  the 
natural  and  which  the  acquired  way  ?     Observe  children 
learning  to  walk. 

28.  What  difference  in  the  bearing  or  carriage  of  per- 
sons is  caused  by  the  direction  given  the  foot  in  walking? 
Take  a  few  steps  very  slowly,  and  study  the  position  of 
the  body  at  each  step. 

29.  In    walking   with    the    feet    parallel,  compare  the 
transverse  space  between  the  tracks  with  the  space  when 
the  toes  diverge. 


December]  ZOOLOGY.  *39 

30.  Which  mode  of  walking  contributes  more  to  erect- 
ness  of  attitude  ?     Why  ?     Test  by  walking  slowly.     It 
will  be  noticed   that   in   walking  with  the  feet  parallel, 
there  is  a  slight  rolling  motion  at  the  hips,  and  that  the 
body  sways  somewhat  from  side  to  side.     The  swaying  is 
increased  since  the  feet  are  usually  placed  a  little  wider 
apart  transversely,  in  order  to  broaden  the  base.     The 
body  is  bent  slightly  forward  when  taking  steps  thus. 

When  the  toes  are  turned  outward,  the  distance  trans- 
versely between  the  feet  is  less,  and  the  swaying  motion 
at  the  hips  is  partially  lost. 

The  body  is  more  easily  held  erect  in  walking  with  the 
diverging  steps. 

The  Indian  in  his  long  journeys  seemed  to  prefer 
carrying  his  feet  parallel,  while  the  white  man  turns  his 
toes  outward,  as  a  rule.  If  one  practices  until  he  can 
walk  well  either  way,  an  alternation  of  the  two  methods 
will  be  found  to  be  restful  when  taking  long  walks. 

31.  By  what  means  is  the  body  protected  from  jars  in 
walking  ?     Which  of  the  above-described  modes  of  walk- 
ing gives  the  more  elastic  step  ? 

32.  With  the  shoe  removed,  notice  how  the  foot  spreads 
gradually  as  the  weight  of  the  body  is  thrown  forward 
upon  it  ;  what  part  of  the  foot  should  touch  the  ground 
first  in  order  to  reduce  the  jar  most  ? 

33.  Why  do  tight  shoes  make  the  step  inelastic  ? 

34.  Why  do   high-heeled  shoes   render  it  difficult  to 
walk  with  the  natural  step  ? 

35.  What  is  the  chief  use  of  the  arms  in  man  ?     To 
what  is  their  difference  in  function,  from  that  of  the  fore 
limbs  in  most  animals,  due  ? 

36.  Compare  their  movements  with  the  wings  of  a  bird  ? 
the  fore  legs  of  the  horse,  dog,  cat,  and  squirrel. 


H°  NATURE   STUDY.  [December 

37.  What  general  modification  in  form  and  attitude  of 
the  trunk  accompanies  the  increasing  freedom  of  move- 
ment in  the  fore  limbs  ? 

38.  In  what  movements  is  the  hand  superior  to  the 
corresponding  part  in  other  animals  ?     Note  the  position 
of  the  thumb  and  fingers. 

39.  What  change  in  the  position  and  attachment  of  the 
arms  is  associated  with  their  great  mobility  ? 

40.  What  substitutes  for  legs  do  such  animals  as  worms 
and  snakes  have  ? 

41.  Study  the  movements  of  a  fish  in  the  aquarium  ; 
what  is  the  chief  organ  of  locomotion  ? 

42.  What  seems  to  have  determined  the  shape  of  the 
body  ? 

43.  How  does  it  turn  itself;  ?     How  does  it  rise  and 
sink? 

44.  Does  it  require  any  effort  on  the  part  of  the  fish  to 
remain  in  the  usual  position  ?     Observe  the  position  in 
which  a  dead  fish  floats. 

45.  By  what  means  is  it  kept  in  an  upright  position? 

46.  Since  the  flight  of  a  bird  through  the  air  and  the 
swimming  of  a  fish  in  the  water  are  somewhat  analogous, 
why  is  it  that  the  modes  of  propulsion  in  the  two  cases  are 
so  very  different  ? 

NOTE.  Additional  topics  will  be  given  under  this  head  in  the 
spring. 

THE   SKELETON. 

It  is  desirable  in  this  study  to  have  some  prepared 
skeletons  ready  for  class  use.  A  human  skeleton  should 
be  procured  if  possible,  both  on  account  of  its  size  and 
of  the  practical  interest  it  possesses  for  pupils.  Skeletons 
may  be  prepared  quite  easily  from  any  small  animal. 


December]  ZOOLOGY,  141 

After  killing  the  animal,  such  as  a  frog,  mouse,  or  bird, 
with  chloroform  or  ether,  cut  all  the  meat  away  that 
comes  off  without  danger  of  breaking  a  bone  or  separ- 
ating a  joint,  and  remove  the  contents  of  the  body  cavi- 
ties. Then  make  a  caustic  potash  solution,  one  ounce  to 
a  pint  of  water,  and  soak  the  carcass  in  this,  at  short  in- 
tervals, removing  the  flesh  as  fast  as  it  softens.  To  re- 
move the  brain  separate  the  skull  from  the  spinal 
column,  and  use  a  crooked  wire.  With  care  in  preparing 
the  solution  so  that  it  will  not  be  too  strong,  the  flesh  may 
be  cleaned  off  before  the  ligaments  soften  enough  to  al- 
low the  bones  to  separate  at  the  joints,  and  one  may  in 
this  way  secure  an  articulated  skeleton.  If  the  bones 
become  separated,  however,  they  may  be  mounted 
diagrammatically  by  sewing  them  to  stiff  cardboard. 

1.  Name  several  animals  that  you  are  sure  have  bony 
skeletons. 

2.  Name  some  that  do  not  have  skeletons. 

3.  Name  some  that  have  the  skeletons  on  the  outside 
of  the  body. 

4.  Of  what  use  is  our  skeleton  to  us?  . 

5.  Of   what  use  are   the   bones  of    our  limbs  ?      Of 
what  additional  use  are  the  bones  of  the  skull  ? 

6.  What  uses  canyon  discover  for  the  ribs?     Notice 
carefully  the  act  of  breathing. 

7.  Note  in  the  prepared  skeletons  the  two  parts  :  the 
trunk,  including  head  and  neck,  and  the  limbs,   upper 
and  lower. 

8.  Can  you  find  such  divisions  in  the  skeleton  of  a 
frog  ?     In  the  bird  ?     The  mouse  ?     The  squirrel  ? 

9.  Which,  on  the  whole,   most  closely  resembles  our 
own  ? 

10.  In  what  respects  are  they  all  alike  ? 


142  NATURE   STUDY.  [December 

11.  Which   is  most  unlike  our  own  ?     Which  animal 
most  closely  resembles  us  in  action  ? 

12.  Examine  the  skull    of   each.     Wherein  do  they 
differ  most  ? 

13.  Which  contains  relatively  the  largest  cavity  ? 

14.  Which     animal     shows   the    greatest    amount   of 
intelligence  ? 

15.  Which  the  least  ? 

1 6.  Note  the    bones  composing  the  skull.     Look  for 
the    notched    lines  where    they   are  joined.     These   are 
called  sutures. 

17.  Do  the  bones  move  one  upon  the  other? 

18.  Do  they  form  a   complete  box?     Are    any  of  the 
skulls  incomplete  in  this  respect  ? 

The  large  opening  at  the  base  of  the  human  skull,  the 
foramen  magnum,  is  the  passage  for  the  spinal  cord  ; 
the  smaller  openings,  front  and  back,  are  for  the  passage 
of  nerves  and  blood-vessels. 

19.  How   can   you    account    for  the  difference  in  the 
shape  of  the  heads  of  these  animals  ? 

20.  What  gives  this  difference  of   aspect   chiefly,  the 
bones  of  the  face,  or  those  of  the  skull  ? 

21.  In  what  respects  are  the  trunks  all  alike  ?     Which 
are  most  alike  ?     Between  which  are  the  greatest  differ- 
ences ? 

22.  Which   of  the   animals   are   most   alike   in   their 
resting  attitude  ? 

23.  Which  are  most  alike  when  in  action  ? 

24.  Can  you  tell  whether  it  is  the  movements  that  de- 
termine the  general  form  of   an  animal,  or  the  shape 
that  determines  the  general  movements  ? 

25.  Can  you  see  how  the  movements  of  the  animals  have 
determined  any  of  the  features  noticed  in  the  trunk  ? 


December]  ZOOLOGY.  143 

26.  Which  has  done  more   to  give  shape  to  the  trunk 
as  a  whole,  the  position  of   the   body  while  in  motion  or 
while  at  rest  ?     Are  all  the  animals  alike  in  this  respect  ? 

27.  In  which  animal  is  the  trunk  the  most  flexible  ? 

28.  How  is  the  trunk  rendered  flexible  ?     In  what  part 
is  it  most  rigid  ?     Why  ? 

29.  What  are  the  advantages  we  derive  from  the  flexi- 
bility of  the  trunk  ?     Between   the  vertebrae  are  elastic 
pads  of  cartilage.     Each  pad  is  fastened  to  the  vertebra 
above  and  the  one  immediately  below  it.     The  elasticity 
of  the  pads  and  their  attachments  permit  of  flexibility 
without  the  gliding  of  one  bone  over  another,  as  in  most 
joints,  which  in  this  case  would  endanger  the  delicate 
spinal  cord  within.     These   pads,  with  the  curves  of  the 
spinal  column,  are  usually  thought  to  be  largely  instru- 
mental in  protecting  the  brain  from  jars  and  shocks  inci- 
dent to  walking,  jumping,  and  similar  movements.     That 
this  is  not  so  to  any  great  extent  is  evident  to  every  one 
who  has  unexpectedly  stepped  into  a  hole  a  few  inches 
deep.     When  knowingly  taking  such  a  step,  the  leg  is  so 
held  as  to  remove  the  jar  by  bending  slightly  at  the  joints ; 
otherwise  the  position  does  not  admit  of  this  bending, 
and  the  shock  is  conveyed  to  the  base  of  the  spinal  col- 
umn  and  thence  to  the  brain,  and,  even  in  a  trivial  mis- 
step, it  is  one  that  is  very  generally  dreaded. 

30.  In  which  animal  are  the  fore  and  hind  limbs  most 
alike  ?     In  which  most  different  ? 

31.  Which  animal  uses  its  fore  limbs  most  nearly  as 
we  do  ? 

32.  In  which  animal  is  there  the  greatest  difference  be- 
tween the  fore  and  hind  limbs  ?     In  which  is  there  the 
greatest  similarity  ? 

33.  In  which  animal  is  there  the  greatest  difference  in 


144  NATURE   STUDY.  [December 

the  use  of  the  fore  and   hind    limbs  ?     Note  the  relative 
length  of  the  fore  and  hind  limbs. 

34.  Count  the  bones  in  the  fore  limb  or  arm  of  a  man, 
and  compare  with  the  other  skeletons. 

35.  In  which  skeleton  do  the  bones  admit  of  the  most 
varied  movement  ?     Which  the  least  ? 

36.  What  is  the  chief  use  of  the  fore  limb  that  has  the 
greatest  range  of  movement  ? 

37.  Note  the  relative  length  of  the  bones  in  the  upper 
and  lower  arm  in  each  animal. 

•38.  In    which   animal   are   they   relatively   strongest  ? 
Note  the  relative  length  in  each  case. 

39.  Can  you  find  bones  in  the  fore  limbs  of  the  other 
animals  to  correspond  with  all  those  in  the  arm  of  man  ? 

40.  Which  is  most  like  man's  arm  in  use  ? 

41.  How  are  the  upper  limbs  fastened  to  the  trunk  in 
each  case  ?     Are  they  all  alike  in  this  respect  ? 

42.  What  cause  can  you  see  for  the  difference,  in  this 
particular,  between  the  mouse  and  bird  ?      Between  man 
and  the  mouse  ? 

43.  In  which   animal   are   the   hind   limbs  relatively 
strongest  ?     How  do  they  compare  with  the  fore  limbs  as 
to  the  number  of  the  bones  ? 

44.  Note  their  attachment  to  the  trunk  ;  how  do  they 
differ  in  this  from  the  fore  limbs  ? 

45.  How  have  the  bodily  movements  affected  the  hind 
limbs  in  each  case  ? 

46.  How  do  the  movements  of  the  bones  in  the  hind 
limbs  differ  from  those  of  the  corresponding  bones  in 
the  fore  limbs  ?     Note  the  relative  length  of  the  bones 
of  the  hind  limb,  and  compare  with  the  fore  limb. 

47.  How  has  the  attitude  of  the  body  modified  the 
hind  limbs  in  each  case  ? 


December]  ZOOLOGY.  145 

48.  How  are  they  adapted  to  the  movements  of  the 
animal  ? 

49.  In  which  skeleton  is  the  foot  most  unlike  the  hand  ? 
In  which  is  the  greatest  resemblance  ? 

50.  In  which  are  the  movements  and  uses  of  the  foot 
and  hand  most  nearly  alike  ?     In  which  most  unlike  ? 

51.  Locate   in    four-footed   creatures   like  the  horse, 
dog,  cat,  etc.,  these  joints  found  in  man  ;  toe  joints,  heel 
joints,  knee  joint,  hip  joint,  wrist  joint,  finger  joints,  el- 
bow joint,  and  shoulder  joint. 


Botany 

A  few  observations  should  be  kept  up  this  month  on 
the  effects  of  frost  and  freezing  on  plants. 

1.  Sometime  during  a  hard  freeze  examine  the  smaller 
twigs.     Are  they  frozen  through  ?     How  protected  ? 

2.  Open  the  buds  ;  are  they   frozen  ?     What  are  the 
ways  by  which  the  buds  are  protected  ? 

3.  Are  they  wet  through  when  it  rains  ? 

4.  Can  you  still  distinguish  the  newly  formed  wood  ? 

5.  Is  any  part  of  the  twig  still  green  ? 

6.  Look  for  seeds  of  weeds  and  other  plants  that  have 
been  scattered  about  ;  do   they   freeze  ?     Can  you  find 
any  that  are  sprouting  ? 

7.  Can  you  tell  whether  or  not  it  kills  them? 

8.  Are  those  that  are  buried  in  a  few  inches  of  earth 
frozen  ? 

9.  Look   for  acorns  and   other   nuts  ;  how  does  the 
freezing  affect  them  ? 

10.  Can  you  find  any  plants  whose  stems  have  been 
killed,  but  whose  roots  are  still  living  ? 

11.  Do  the  roots  of  the  trees  freeze  ? 

12.  Can  you  find  any  injurious  effects  of  frost   and 
freezing  on  the  trunks  of  trees  ? 

13.  Can  you  find  any  growing  plants  ? 


146 


THE  LEVER. 

It  is  the  intention  that  the  lessons  given  upon  the 
lever  should  supplement  those  given  in  Zoology  this 
month  on  the  movements  of  animals.  The  pupils  must 
provide  themselves  with  small  sticks  about  a  foot  long, 
and  a  block  of  wood,  stone,  or  iron  an  inch  or  two  in 
diameter. 

1.  Suppose  the  block  were  a  weight  that  could  not  be 
conveniently  lifted  by  hand,  illustrate  with  the  stick  the 
different  ways  in  which  a  bar  might  be  used  in  lifting  it. 

2.  The  pupil  should  work  with  this  problem  until  he 
finds  the  three  ways  of  using  the  stick  as  a  lever.     He 
should  see  that  in  each  case  there  is  a  fixed  point  about 
which  the  lever  moves  which  is  called  the  fulcrum.     Also 
that  in  each  there  is  a  point  where  the  power  is  applied 
and   another   point    where    the    weight    is   placed.     He 
should  note  that  the  form  of  the  lever  depends  upon  the 
relative  position  of  these  three  points,  which  are  usually 
represented  by  the  letters  F,  Wt  P.     The  distance  from 
F  to  P  is  the  power  arm,  and  from  F  to  W  the  weight 
arm  of  the  lever.     The  three  kinds  are  distinguished  as 
first-class,  when  F  is  between  P  and  W ;  second-class, 
when  W  is  between  F  and  P,  and  third-class,  when  P  is 
between  F  and  W.     It  will  be   noticed  that  one  need 
remember  only  the  point  which  lies  between  the  ends  in 

M7 


148  NATURE   STUDY.  [December 

order  to  tell  the  class  of  lever,  and  in  the  order  of  first, 
second,  and  third,  the  letters  stand  F  W  P,  initials  which 
no  pupil  of  Cook  County  Normal  School  will  find  it 
difficult  to  remember. 

3.  How  must  the  lever  of  the  first  class  be  used  to  lift 
the  greatest  weight  ?     What  do  you   notice  about   the 
relative  length  of  the  two  arms  P  F  and  W  Ft 

4.  Use  it  again  so  that  it  will  be  of  the  least  use  in 
lifting  a  weight ;  is  there  any  advantage  in  such  use  ? 
Note  again  the  relative  length  of  the  two  arms. 

5.  In  the  same  way,  use  the  second  and  third  class 
forms  of  the  lever.     Note  each  time  the  relative  length 
of  the  two  arms,  and  also  as  to  whether  the  advantage 
gained  in  each  case  is  one  of  power  in  lifting  the  weight 
or  of  distance  through  which  it  is  moved. 

6.  Can  the  lever  be  so  used  that  there  will  be  no  gain 
of  either  power  or  distance  ? 

7.  Is   it  possible   to   gain  power   with   each  form  of 
lever  ? 

8.  What  do  you   notice  about   the    relative   distance 
through  which  the  power  and  weight  move  in  the  second 
class  lever?     Notice  the  same  in  the  third  class. 

9.  What  determines  the  distance  through  which  the 
power  or  weight  shall  move  ? 

10.  What  forms  of  the  lever  have  you  seen  workmen 
use  ?     When  do  they  use   the   first   class  ?     When    the 
second  class  ?     When  the  third  class  ? 

11.  Study  some  of  the  parts  of  the  animal  body  as 
levers.     What  are  their  uses  ? 

12.  In   studying   the   levers   of   the  body,   the  pupil 
should  first  be  required  to  fix  the  limits  or  ends  of  the 
lever,  then  the  fixed   point  or  fulcrum,  then  the  weight 
and  power.     If  this  order  be  followed  carefully,  one  step 


December]  PHYSICS.  149 

at  a  time,  it  is  not  difficult  to  fix  the  levers  of  the  body 
and  to  tell  the  different  orders. 

13.  In  the  manner  suggested,  locate  and  describe  the 
levers  concerned  in  the  following  movements  :  (i)   Flex- 
ing the  forearm  ;  (2)  extending  forearm  ;  (3)   lifting  the 
entire   arm   outward    and    upward  from  the  body  ;  (4) 
opening  the  mouth  ;  (5)  closing  the   mouth  ;   (6)    neck 
rigid,  tipping  head  backward  and  forward  ;    (7)  throw- 
ing  the    head    from    one    shoulder    to   the    other ;    (8) 
straightening   up  when  the  body  is  bent  at  the  hips  ; 
(9)  lifting  the  body  to  tip-toe  position  ;  (10)  standing  on 
the  heels  and  lifting  the  toes  ;  (n)  hold  the  foot  clear 
of  the  floor  and  tap  it  with  the  toes  ;   (12)  in  same  posi- 
tion lift  the  toes  ;  (13)  flexing  the  lower  part  of  the  leg  ; 
(14)  in  swinging  the  leg  at  the  hip  joint ;  (15)  in  the  rib 
movement  in  breathing. 

14.  What  class  is  most  commonly  found  in  the  animal 
movements  ? 

15.  What  advantages  are  derived  in  most  cases  from 
the  form  employed  ? 

16.  What  disadvantages  in  the  lever  of  the  forearm  ? 

17.  In  what  position  can  you  get  the  most  strength  or 
lifting  power  in  the  forearm  ?     Test  this  by  straightening 
the  arm  out  on  a  table  and  then  slowly  flexing  it  against 
the  upper  arm. 

1 8.  Can  you  find  similar  levers  used  in  the  movements 
of  other  animals  ? 

19.  Why  is  it  so  difficult  to  hold   an   animal   by  its 
hind  legs  ?     Note  the  leverage  and  the  class  of  lever  in 
the  four-footed  animals  in  the  leg  below  the  heel. 

20.  What  kind  of  a  lever  is  there  in  the  wing  of  a  bird  ? 

21.  How  do  animals  move  that  are  not  provided  with 
bones  for  levers  ? 


15°  NATURE    STUDY.  [December 

22.  The  pupil  should  be  asked  to  trace  out  the  levers 
that  may  be  found  in  the  wheel  work  of  different  ma- 
chines. 

EQUILIBRIUM  OF  BODIES. 

In  this  subject  many  interesting  experiments  may  be  de- 
vised and  many  illustrations  may  be  drawn  from  the 
experience  of  the  pupil  which  will  acquaint  him  some- 
what with  the  force  of  gravitation  and  its  action  upon 
bodies  of  different  size,  shape,  and  mass. 

1.  When  a  ruler  or  any  body  is  held  at  rest  in  the  hand 
is  there  any  evidence  that  there  is  a  force  acting  upon 
it  ?     How  is  that  force  measured  ?     What  is  the  meas- 
urement of  it  called  ? 

2.  When  the  hand  is  removed,  what  happens  to  the 
object  ?     What  kind  of  a  line  does  it  follow  in  its  move- 
ment ?     What  is  this  particular  line  called  ? 

3.  Can  you  balance  every  body  upon  a  point  of  sup- 
port that  is  smaller  than  the  base  of  the  object  ?     Can 
you  balance  any  of  the  bodies   in  more  than  one  posi- 
tion ?     Try  such  bodies  as  blocks  of  wood,  balls,  sticks, 
etc. 

4.  The  point  in  a  body  upon  which  the  body  will  bal- 
ance  in   any  position  is  called    the   center   of   gravity. 
Where   is   such   a   point   in   a   ball    of   wood    or  iron  ? 
Where  is   it  in  a  cube  of   wood  ? 

5.  In  order  to  find  the  center  of  gravity  in  any  body, 
suspend  it  from   some  point  and  note  the  direction  of 
the  vertical  line  from  the  point  of  suspension  through  or 
across  the  body  ;   ivnv  suspend  it  from  another  point  and 
note  when  the  vertical  line  from  the  second  point  of  sus- 
pension intersects  the  first.     The  point  of  intersection  is 
the  center  of  gravity.     Does  the  center  of  gravity    lie 
within  the  body  or  on  its  surface  ? 


December]  PHYSICS.  IS1 

6.  Is  it  always  within  the  body  ?     Where  is  it  in  a  ring 
or  hoop  ?     In  a  hollow  sphere  ? 

7.  The  vertical    line   from   the   center   of   gravity    is 
called  the  line  of  direction.     In   considering  the  stability 
of  bodies  it  is  of  the  highest  importance  to   keep  the 
center  of  gravity  and  the  line  of  direction  constantly  before 
the  mind. 

8.  When  a  cube  rests  on  a  table  on  one  side,  can  you 
see  where  the  line  of  direction  must  be  ? 

9.  When  you  roll  the  cube  from  one  side  so  that  it  will 
rest  upon  another,  what  kind  of  a  line  does  the  center  of 
gravity  describe  ? 

10.  Compare  the  rolling  of  a  ball  with  the  turning  of 
the  cube  ;  which  is  easier?     How  does  the  line  described 
by  the  center  of  gravity  in  the  ball  differ  from  that  de- 
scribed by  the  cube  ? 

1 1  Place  a  cone  on  its  apex  and  try  to  balance  it  ;  as 
it  falls  over,  what  kind  of  a  line  is  described  by  the  cen- 
ter of  gravity  ? 

12.  A  body   is  said  to  have  stable  equilibrium  when 
any  movement  which  disturbs  its  equilibrium  raises  the 
center  of  gravity  ;  when  any  such  movement  lowers  the 
center  of  gravity  it  is  in  unstable  equilibrium.      When 
the  center  of  gravity   moves  in  a  line  parallel  with  the 
floor  or  other  support  the  body  is  in  indifferent  or  neutral 
equilibrium.     Test  various  bodies  that  you  have  handled, 
such  as  the  cube,  cone,  pyramid,  ball,  prism,  etc.     These 
may  be  modeled  in  clay. 

13.  Can  you  place  a  cone  in  stable  equilibrium  ?     In 
unstable  equilibrium?     In  indifferent  equilibrium? 

14.  In  tipping  any  body  over  notice  the  path  of  the 
line  of  direction  at  the  point  where  the  body  refuses  to 
come  back  to  its  original  position.     Under  what  condi- 


I52  NATURE    STUDY.  [December 

tions  will  the  body  always  resume  its  first  position  when 
its  equilibrium  is  disturbed  ? 

15.  Under  what  conditions  do  you  find  a  body  most 
stable  ?     Least  stable  ? 

1 6.  Where  is  the  center  of  gravity  of  your  own  body  ? 

17.  Why  is  it  more  difficult  to  push  one  over  forward 
than  backward  ?     Why  may  one  be  easily  pushed  over 
sidewise  ? 

1 8.  Why  is  a  wagon  with  a  high   load  of  hay  more 
easily  upset  than  one  with  the   same   weight,   but  less 
bulk? 

19.  Can    you    understand    why    tight   rope   walkers 
always  carry  a    heavy   balancing   pole  ?     Why    does   a 
porter  with  a  pack  on  his  back  lean  forward,  while  if 
the  same  weight  were  in  a  pail  and  carried  in  his  hand 
he  would  walk  upright  ? 

20.  Why  is  it  difficult  to  walk  on  stilts  at  first  ?     Why 
is  it  impossible  to  stand  steadily  upon  them  ? 

21.  Why  does  a  ball  roll  down  hill?     Why  does  a  bi- 
cycle rider  fall  over  sidewise  when  he  stops  ?     A  some- 
what more  difficult  thing  to  explain  is  why  he  and  his 
wheel  can  remain  upright  while  in  motion  ;  can  you  see 
the  reason  ? 

22.  Thrust  a  pin  half-way  to  the  head  in  a  medium 
sized  cork.     Stick  two  penknives  into  the  cork  one  op- 
posite the  other  and  so  that  the  handles  will  slant  down- 
ward below   the  end   of   the  pin.     Why   will  the  cork 
remain  upright  balanced  upon  the  pinhead  ? 

HEAT. 

A  study  of  the  following  topics  in  this  subject  should 
be  applied  in  the  explanation  of  whatever  natural  phe- 
nomena the  pupils  may  have  observed,  which  rests  upon 


December]  PHYSICS.  153 

the  principles  here  illustrated  as  a  cause.  Among  the 
points  which  may  be  mentioned,  are  the  cooling  of  sur- 
faces upon  which  dew  is  formed,  the  origin  and  direction 
of  air  currents,  modes  of  ventilation,  effects  of  different 
kinds  and  colors  of  clothing  upon  the  heat  of  the  body, 
and  so  on.  Careful  consideration  of  the  differences  in 
bodies  as  to  their  capacity  for  heat  will  assist  to  a  clearer 
comprehension  of  the  relation  of  land  and  water  masses 

to  climate. 

Liquefaction. 

1.  Take  two  wide-mouthed  bottles  as  nearly  alike  as 
possible  and  fill  one  with  ice  and  the  other  with  the  same 
weight  of  water  ;  place  both  in  a  pan  of  boiling  water 
over  a  lamp  or  gas  jet. 

2.  Note  the  temperature  of  each  at  intervals  until  the 
ice  is  all  melted. 

3.  Have  the  two  vessels  received  the  same  amount  of 
heat  ?     Note  the  conditions  carefully  under  which  each 
is  placed. 

4.  What  difference   in   temperature   when   the  ice  is 
melted  ? 

5.  Had  the  temperature  of  the  bottle   with  the   ice 
in  it  risen  at  all  at  the  moment  it  was  melted  ?     What 
change  did  the  heat  bring  about  in  the  bottle  ? 

6.  After  the  ice  has  melted,  does  the  thermometer  in- 
dicate any  change  ? 

7.  Remove  to  a  sand  bath  and  raise  the  temperature 
of  the  water  until  it  boils.     A  thin  glass  beaker  or  vessel 
of  tin  should  be  used  for  the  purpose. 

8.  What  is  the  temperature  at  which  it  boils  ?     Hold 
the  thermometer  in  the  steam  over  the  liquid. 

9.  Increase  the  heat  by  means  of  more  burners ;    does 
the  temperature  rise  ? 


154  NATURE    STUDY.  [December 

10.  What  has  been  accomplished  by  the  heat  in  these 
experiments  with  the  water  and  ice  ? 

11.  When  heat  is  applied  to  a  body  or  fluid  does  it 
always  show  itself  as  temperature  ?     When  not  shown  as 
temperature  how  is  it  expressed  ? 

Conduction  of  Heat. 

1.  In  heating  the  metallic  rods  (i)  at  one  point,  what 
did  you  notice  as  to  the  effect  upon  the  entire  rod  ? 

2.  Did  the  parts  farthest  from  the  flame  become  heated 
by  radiation  ? 

3.  What  parts  became  heated  first?     What  parts  last? 

4.  How  does  the  heat  get  from  one  end  of  the  rod  to 
the  other? 

5.  Procure  pieces  of  different  kinds  of  wire  or  rods, 
such  as  copper,  iron,  and  brass,  one   foot  long.     Twist 
them  together  in   pairs  for  two  inches  at  one  end  and 
from  the  point  where  they  are  twisted  spread  them  apart 
in  something  of  a  U  shape.     At  some  distance  from  the 
twist,  and  at  equal  distances  from  each  other,  fasten  by 
means  of  sho.emaker's  wax  small  bullets  or  shot  to  each 
wire.     Support  horizontally  so  that  the  twisted  ends  may 
rest  in  the  flame  of  the  lamp.     Protect  the  balls  from  the 
radiant  heat  from  the  lamp  with  a  screen. 

6.  From   which  wire  do  the  balls  drop  first  ?     What 
does  that  indicate  ? 

7.  Which  is  the  last  in  losing  the  balls? 

8.  Bodies  which  become  heated  from  particle  to  parti- 
cle as  in  the  case  of  the  wires  are  called  conductors. 

9.  What  difference  between  heating  by  radiation  and 
conduction  ? 

10.  Which  is  the  better  conductor,  iron  or  copper  ? 
Brass  or  copper  ?     Iron  or  brass  ? 


December]  PHYSICS.  155 

11.  Why  does  a  piece  of  iron  become   heated  when 
held  in  the  hand  ?     Why  does  it  at  first  feel  cold  ? 

12.  Why  does  wood   feel   less  cold   than  iron  to  the 
touch  ?     Why  are  iron  handles  sometimes  tipped  with 
wood  ? 

13.  Is  the  iron  really  colder  than  the  wood  ? 

14.  Why  does  our  bed  feel  cold  at  first  ?    How  does  it 
become  warmed  ? 

15.  Why  does  a  blanket  seem  warmer  than  a  sheet  ? 

16.  Why  is  linen  clothing  worn  in  summer  and  woolens 
in  winter  ? 

17.  Why  is  it  regarded  safer  for  one's  health  to  wear 
light  woolens  next  the  body,  even  in  summer  ? 

Convection. 

1.  Fill  a  good-sized   test-tube,  or,  better  still,  a  glass 
beaker,   nearly   full   of  water.     Sprinkle   into  it  a  little 
powdered  chalk  and  heat  gradually. 

2.  Look  closely  for  any  currents  that  may  be  started 
as  indicated  by  the  particles  of  chalk. 

3.  Make  a  drawing  of  the  beaker,  and  mark  with  ar- 
rows the  direction  of  the  currents. 

4.  Where  does  the  water  become  heated  first?     How 
do  the  other  portions  become  heated  ? 

5.  Using   light    pieces    of    paper,   look    for    currents 
of  air  in  the  room.     Try  the  space  over  the  stove  or 
register  ;  also  the  cracks  above  the  doors   and  at  the 
bottom.     Open  the  window  at  top  and  bottom  half  an 
inch.     Use  a  lighted  candle  or  taper  in   looking  for  a 
draught. 

6.  What  is  the  cause  of  the    air   movements  in  the 
room  ? 

7.  Can  you  account  for   their   direction  ?      Using  a 


IS6  NATURE   STUDY.  [December 

thermometer,  find  out  where  the  lowest  temperature  is  in 
the  room,  and  whether  it  is  at  the  top  or  bottom. 

8.  Recall  the  experiment  illustrating  expansion  of  air, 
which  was  performed  in  November. 

9.  How  are  those  parts  of  the  room  distant  from  the 
stove  or  register  heated  ? 

10.  Compare  the  heating  of  the  air  in  the  room  with 
the  heating  of  the  water  in  the  beaker. 

1 1.  The  manner  in  which  the  water  in  the  beaker  and 
the  air  in  the  room  are  heated  is  known  as  convection. 

12.  How  does  convection  differ  from  conduction  ? 

13.  Fill   a   test-tube    nearly   full    of   water,   and  very 
cautiously  heat  it  near  the  top  in  the  flame  of  the  lamp  ; 
test  at  intervals  with  a  thermometer  the  top  and  bottom 
portions.     A  small  piece  of  ice  held  at  the  bottom  of  the 
water  by  a  fragment  of  lead  or  a  pebble  will  make  the 
contrast   stronger.     Great   care    must   be    exercised    in 
heating  the  test  tube   in  the  last  experiment,  or  it  will 
crack  ;   why  is  this  ? 

14.  Does  the  water  become  heated  throughout  more 
or  less  quickly  than  before  ? 

15.  What  makes  the  difference  ?     By  what  process  is 
it  heated  in  the  latter  case  ? 

16.  Why  is  it  not  heated  by  convection  ? 

17.  Study  the  mechanism  of  the  kitchen  range,  and 
explain  how  the  water  in  the  boiler  is  heated. 

1 8.  When  the  fire  is  starting,  which  part  of  the  boiler 
gets  warm  first  ?     Place  the  hands  at  different  points  on 
the  outside. 

19.  How  does  the  water  in  the  lake  become  heated  ? 
Explain  why  it  is  always  cold  a  little  distance  below  the 
surface.     How  does  the  ocean  beccme  heated,  by  con- 
duction or  convection? 


December]  PHYSICS.  157 

20.  How  does  the  sun  warm  the  earth  ? 

21.  Is  the  air  warmed  directly  by  the  sun  ? 

22.  Can   you   see  any  reason  why  it   is  colder  on  a 
mountain  peak  than  it  is  on  a  low  plain  ? 

23.  Hold  a  piece  of  plain    glass   between   the  hand 
and  the  sun  ;  can  you  notice  any  change  in  the  amount 
of  heat  that  reaches  the  hand  ? 

24.  Instead  of  the  plain  glass,  use  a  common  magnify- 
ing glass  or  lens  ;  hold  it  so  that  the  sunlight  passing 
through  it  is   reduced  to  a  small  point.     Allow  this  to 
fall    upon   the    hand    or  upon    paper.       How   can    you 
account  for  the  great  heat  at  that  point  ?     Is  it  hot  out- 
side the  area  of  this  spot  ?     Try  to   make  a  drawing 
showing  by  lines  the  way  the  heat  must  come  to  the  lens 
and  the  way  it  must  leave  it  on  the  opposite  side.     Heat 
bent  out  of  a  straight  course  by  some  substance  which  it 
passes  through  is  said  to  be  refracted.     Compare  reflec- 
tion with  refraction. 

Capacity  for  Heat. 

1.  In   two   vessels   of    the    same    kind,    place    equal 
amounts  of  water  ;  raise  the  water  in  one  of  the  vessels 
to  the  boiling  point  and  take  the  temperature.     Find  the 
temperature  of  the  water  in  the  other  vessel,  and  then 
add  it  to  the  boiling  water. 

2.  What  is  the   temperature    of  the   mixture  ?     How 
much  was  the  cool  water  warmed  ?     How  much  was  the 
warm  water  cooled  ?     Is  the  number  of  degrees  the  same 
in  both  cases  ?     Is  the  result  what  you  would  expect 
from  the  experiment  ? 

3.  Take  a  piece  of  lead  weighing  three  or  four  ounces. 
If  not  already  in   a  sheet,  pound   it  out  thin  and   roll 
loosely.     Suspend  in  a  vessel  of  boiling  water,  and  allow 
it  to  remain  until  it  has  the  same  temperature  as  the 


NATURE  STUDY.  [December 

water.  Into  another  vessel  put  a  weight  of  water  equal 
to  that  of  the  lead,  and  take  its  temperature.  As  quickly 
as  possible  drop  the  lead  into  this  vessel  of  water  and 
take  the  temperature.  How  much  does  the  temperature 
of  the  water  rise  ?  How  much  does  that  of  the  lead 
fall  ?  What  are  the  sou  rces  of  error  in  these  experiments  ? 
In  what  way  will  the  errors  change  the  results  ? 

4.  In  the  same  way  use  different  substances,  as  zinc, 
sheet  iron,  tin,  brass,  and  copper. 

5.  Notice  how  much  the  water  gains  in  each  case  and 
how  much  the  metal  loses. 

6.  How  much  heat  must  have  been  in  the  metal  when 
taken    from  the   boiling  water  ?     What  became  of  this 
when  it  was  dropped  into  the  cooler  water  ? 

7.  Does  the  thermometer  always  tell  us  when  heat  is 
added  to  a  substance  ?     Recall   the  experiment  of  the 
melting  ice  in  the  November  work. 

Sources  of  Heat. 

1.  How  do  we  warm  our  houses  ?     What  are  necessary 
in  order  that  we  may  have  a  fire  ? 

2.  When  the  wood  or  coal  burns  what  kind  of  a  change 
takes  place  ?     (See  Chemistry  for  November.) 

3.  Have  you  ever  known  heat  to  be  produced  without 
the  use  of  fire  ? 

4.  Try  rubbing  a   nail  with  a  file.     Rub  two  sticks  to- 
gether.    Rub   the   edge   of   a   penny    over   the   sleeve. 
What  results  in  each  case  ? 

5.  Pound  a  nail  on  a  stone  or  iron  block  with  a  ham- 
mer ;  what  is  the  result  ? 

6.  What  is  the  real  difference  between  the  two  ways 
of  getting   heat,  that  of  burning  the  wood,  and  that  of 
making  it  warm  by  rubbing  it  ? 


PREPARATION  OF  OXYGEN. 
Materials  Needed. 

1.  Test  tubes,  one  for  each  pupil  if  possible,  about  six 
inches  long  and  three-quarters  of  an  inch  in  diameter. 

2.  A  six-ounce  Florence  flask. 

3.  Corks  to  fit  the  above. 

4.  Glass  tubing  having  a  bore  of  about  three-sixteenths 
of  an  inch.     A  piece  about  eight  inches   long  for  each 
pupil.      Bend  the  tubes  at  a  right  angle  two  inches  from 
one  end,  and  put  the  short  end  through  a  hole  in  the  cork. 

5.  Glass  bottles  with  wide  mouths,  at  least  one  for  each 
pupil,  and  a  few  empty  glass  fruit  jars.     Morphia  bottles 
are  very  useful. 

6.  A  pneumatic  trough.     Any  vessel  holding  five  or  six 
inches  of  water  will  answer.     A  small  bench  with  a  hole 
in  the  center  must  be  used  for  supporting  inverted  vessels 
in  the  water  with  their  mouths  below  the   surface.     To 
make  this  take  a  strip  of  tin  about  eight  inches  long,  four 
inches  wide,  and  bend  up  two  inches  at  each  end.     This 
will  be  strong  enough  to  support  small  jars  and  bottles. 

7.  Alcohol  lamps  or  bunsen  burners. 

8.  About  an    ounce    of   potassium    chlorate    and     an 
equal  amount  of  black  oxide  of  manganese  for  each  pupil. 
Test  these  materials  by  powdering  a  little  of  the  potas- 
sium chlorate  and  mixing  with  the   same  amount  of  the 

159 


1 60  NA  TURE  S TUD  Y.  [December 

black  oxide  and  heating  in  an  open  tube  ;  if  the  mixture 
melts  quietly  they  are  safe  ;  if  slight  explosions  occur, 
throw  the  materials  away,  as  they  are  not  pure  and  are 
dangerous. 

Experiments. 

1.  Mix  the  powdered  crystals  of  the  chlorate  with  an 
equal   amount  of  the  black  oxide  ;  put  about   one  inch 
depth  of  this  into  a  test  tube  and  fix  with  a  cork  having  a 
tube  through  it  as  described  above.     Fill  one  or  more 
small    bottles    with   water  and  invert  in  the  pneumatic 
trough,  which  should  have  four  or  five  inches  of  water  in 
it.     Place  one  of  these  upon  the  bench  with  the  mouth 
over  the  hole.     Support  the  test  tube  over  the  flame  so 
that  the  end  of  the  glass  tube  will  be  under  the  surface 
of  the   water  in  trough,  but  not  under  the  bottle   on  the 
bench.     After  the  bubbles    have  escaped   for  a  few  mo- 
ments, arrange  the  end  of  the  tube  under  the  hole  in  the 
bench  so  that  they  will  rise  into  the  bottle. 

2.  Why  not  put  the  end  of  the  tube  under  the  bottles 
at  once  ? 

3.  Why  fill  the  bottle  first  with  water? 

4.  Can   you    see  anything   passing   out  through   the 
tube  ? 

5.  What  change  do  you  notice  in  the  materials  in  the 
test  tube  ? 

6.  What  is  the  nature  of  the  substance  rising  into  the 
bottle  of  water  ? 

7.  When  the  water  has  left  the  bottle,  remove  it  from 
the  hole,  but  keep  the  mouth  below  the  surface.     If  gas 
still  comes  off,  collect  it  in  another  bottle. 

8.  Slip  a  piece  of  glass  as  a  cover  under  the  bottle 
filled  with  gas,  and  holding  it  tightly  in  place,  remove 
the  bottle  and  turn  it  quickly  right  side  up. 


December]  CHEMIS  TR  Y.  1 6 1 

9.  Provide  a  number  of  fine  splinters.     Light  one  of 
them,  and,  when  fairly  blazing,  blow  it  out  and  quickly 
thrust  the  glowing  end  into  a  jar  or  bottle  that  contains 
air  ;  note  carefully  all  that  happens. 

10.  Light  again,  and  in  the  same  manner  thrust  it  into 
the  jar  filled  with  gas  from  the  test  tube  ;  what  difference 
do  you  notice  ? 

11.  What  evidence  that  there  is  something  in  the  jar 
different  from  air  ? 

12.  With  a  fresh  supply  of  gas,  repeat  the  experiment 
suggested  above  in  (9),  using  a  short  piece  of  a  candle. 
Fasten  a  light  piece  of  wire  around  the  candle  by  which 
it  may  be  lowered  into  the  jar. 

13.  After  the  pupils  have  made  oxygen  for  themselves, 
it  may  be  desirable  to  have  a  larger  quantity  and  have  it 
collected  in  the  fruit  jars.     To  do  this  take  about  an 
ounce  of  the  potassium  chlorate  and  mix  with  the  man- 
ganese as  before,   and   use  the   Florence   flask.      Heat 
gradually,  and  when  enough  has  been  collected  remove 
the  end  of  the  tube  from  the  water  before  removing  the 
flame.     If  this  precaution  is  not  observed,  the  water  will 
run  back  into  the  flask  and  break  it. 

14.  Put  a  small  amount  of  sulphur  into  a  thimble  and 
ignite  it ;  by  means  of  a  wire  wrapped  around  it  for  a 
handle,  lower  it  into  a  jar  of  the  gas. 

15.  Ignite  a  piece  of  well-charred  charcoal  and  lower 
into  a  fresh  jar  of  gas. 

16.  Fasten  a  small  splinter  to  an  iron  wire,  and  after 
lighting  lower  it  into  a  jar  of  the  gas. 

17.  Get  a  worn-out  watch  spring  from  a  jeweler  and 
draw  the   temper  by  heating,  and   then   straighten   it ; 
fasten  to  a  stick  as  in  (16)  and,  after  igniting,  lower  it  into 
a  jar  of  the  gas. 


162  NATURE  STUDY.  [December 

1 8.  In  the  same  way  try  a  narrow  ribbon  of  zinc. 

19.  In  the  foregoing  experiments,  does  the  gas  in  the 
jars  burn  ? 

20.  In  what  respects  is  it  like  air  ? 

21.  What  happens  after  burning  a  substance,  as  wood, 
in  the  jar  for  some  time  ?    Compare  this  result  with  what 
was  observed  when  burning  a  taper  in  a  bottle  of  air. 

22.  The  gas  collected  in  the  jars  used  in  these  experi- 
ments is  called  Oxygen.    It  is  the  element  in  the  air  which 
enables  us  to  have  fires  in  our  stoves  and  grates. 

23.  It  is  also  the  life-giving  element  of  the  air  for  ani- 
mals.    How  does  it  enter  our  bodies  ? 

24.  Why  should   chimneys  have  a  good   draught  to 
make  good  fires  ? 

25.  Why  do  we  fan  or  blow  a  fire  to  start  it  ? 

26.  Why  do  we  need  ventilation  in  a  room  ? 

27.  In  what  respects  does  oxygen  differ  from  the  car- 
bon dioxide  gas  ?     (See  Chemistry  for  November.) 

28.  Write  a  list  of  the  experiments  performed  and  state 
the  results  obtained. 


1.  Has  the  prevailing  wind  changed  direction  within 
the  last  three  months  ?     What  may  be  given  as  causes? 

2.  Has  the  cloudiness  increased  or  diminished  ? 

3.  How  does  the  character  of  the  rains  differ  from 
those  in  September  ?     What  causes  the  difference  ? 

4.  From  what  direction  do  the  heaviest  rains  come? 

5.  In  what  month  has  the  greatest  number  of  fogs 
been  noted  ? 

6.  What  conditions  are  most  favorable  for  the  produc- 
tion of  fogs  ? 

7.  Is  the  wind  more  or  less  variable  than  it  has  been  in 
the  preceding  months? 

8.  What  wind  precedes  the  heaviest  rains  ? 

9.  What  wind  accompanies  clearing  weather  ? 

10.  Is  the  temperature  increasing  or  diminishing  this 
month  ?     What  cause  can   be  given  ?     (See  Astronomy 
for  December.) 

11.  Is  the  rate  of  change  in  temperature  more  or  less 
rapid  than  it  was  in  the  preceding  three  months  ? 

12.  When  have  most  of  the  rains  occurred,  in  the  day- 
time or  during  the  night  ? 

13.  Of  those  rains  which  occurred  in  the  daytime,  did 
the  greater  number  fall  in  the  forenoon  or  afternoon  ? 

14.  Have  the  frosty  mornings  been  followed  by  fair 
or  foul  weather? 

15.  On  what  date  did  the  first  snow  fall  ? 

16.  From  what  direction  do  the  snows  come  ? 

163 


l64  NATURE  STUDY.  [December 

17.  Do  all  the  rains  come  from  the  same  direction  ? 

1 8.  Examine  some  single  snowflakes  closely  ;  are  they 
all  alike? 

19.  Are   they   all  of   regular   form?     Why   are   some 
flakes  larger  than  others  ? 

20.  How  do  snow  clouds  differ  in  appearance  from  rain 
clouds  ? 

21.  How   does   the   history  of   a  snowflake   resemble 
that  of  a  raindrop  ?     In  what  respect  is  it  different  ? 

22.  Does  the  barometer  in  any  way  herald  the  approach 
of  a  snowstorm  ? 

23.  At  what  temperature  did  the  heaviest  snow  fall? 
Did   the  temperature   rise    or    fall    after    the    snowing 
ceased  ? 

STUDY  OF  THE   WEATHER   BUREAU   MAPS. 

24.  Draw  a  line  across  the  map  connecting  the  points 
farthest  south   where  snow   has   fallen   during  the  last 
month.     This    may   be    called    the  snow    line    for    the 
month. 

25.  Where  does  the  snow  line  extend  farthest  south  ? 

26.  Where  is  its  most  northern  point  ? 

27.  How  many   degrees  of  latitude  are  they  apart? 
How  many  miles  are  they  apart  north  and  south  ? 

28.  How  do  the  coast  lines  affect  the  snow  line  ? 

29.  On    which    coast    is    it   farthest    north  ?     Why   is 
it  so  ? 

30.  Which  mountains   have  the    most   marked  effect 
upon  it,  the  Rocky  Mountains  or  Appalachian  system  ? 

31.  How  does  the  course  of  the  storms  for  this  month 
compare  with  that  for  the  preceding  months  ? 

32.  Have  the  courses  of  the  great  rivers  affected,  ap- 
parently, the  direction  of  the  storms? 


December]  METEOROLOGY.  165 

33.  Have  the  mountains  determined  the  course  of  the 
storms? 

34.  Have  there  been  any  great  storms  with  rain  in  one 
part  of  its  area  and  snow  in  another  part  ? 

35.  Contrast  the  Pacific  slope  with  the  Atlantic  as  to 
rainfall  and  temperature  this  month. 


astronomy 

1.  Compare  the  relative  length  of   day  and  night  in 
December  with  that  of  preceding  months. 

2.  What  has  been  the  average  rate  of  change  in  the 
length  of   day  during   the    month  ?     Compare  with  the 
former  months. 

3.  Note  the  position  of  the  noon  shadow  about  the  2ist 
of  the  month.     Has  it  changed  its  position  more  or  less 
rapidly  this  month  than  it  did  in  September  ? 

4.  Stretch  a  string  from  the  top  of  the  upright  piece 
at  the  end  to  the  point  touched  by  the  noon  shadow  in 
September  when  the  day  and  night  were  equal,  and  another 
string  to  the  point  touched  by  the  shadow  in  December 
when  the  day  is  shortest.     Note  the  size  of  the  angle  be- 
tween the  two  lines.     If  possible,  measure  it.     If  these 
two  lines  were  continued  into  space,  what  two  points  in 
the  celestial  sphere  would  be  found  ? 

5.  Note  as  directed   in  September  the  points  on  the 
horizon  where  the  sun  rises  and  sets.     Why  is  it  that  when 
the  shortest  day  is  reached  in  this  month  the  shadow  does 
not  at  once  begin  a  retrograde  movement  on  the  shadow 
stick.     The  time  of  the  shortest  day  of  the  year  is  called 
the  winter  solstice.     This  means  the  sun  stands  still.     Can 
you  see  a  reason  for  the  use  of  the  word  solstice  ? 

6.  How  have  these  positions  changed  since  Septem- 
ber ? 

7.  What  suppositions  can  you  make  regarding  the  earth 
and  sun  which  will  account  for  the  changes  ? 

1 66 


December]  ASTRONOMY.  167 

8.  Suppose  you  were  to  draw  lines  across  the  sky  mark- 
ing the  apparent  path  of  the  sun  every  day  since  Septem- 
ber, what  would  be  the   relation  of  these  lines  to  each 
other  ? 

9.  How  much  of  the  quarter  circle  on  the  horizon  has 
the  sun  traversed  since  the  day  and  night  were  equal  ? 

10.  Compare  the  number  of  degrees  estimated  in  (9) 
with  the  size  of  the  angle  measured  in  (4). 

11.  Can  you  show,  by  means  of  the  globe,  on  the  sup- 
position of  revolution,  what  part  of  the  earth's  orbit  has 
been  traversed  since  the  autumnal  equinox  ? 

12.  How  many  days  have  elapsed  since  then  ? 

13.  Does  the  fraction  of  a  year  which  has  passed  since 
the  equinox  correspond  to  the   part  of  the  orbit  over 
which  the  earth  has  passed  since  then  ? 

14.  What  supposition  can  you  make  that  will  explain 
the  lack  of  correspondence  ? 

15.  Explain,  by  means  of  a  globe,  if  necessary,  why  the 
sun  has  seemed  to  change  its  position  since  September. 

16.  Write  a  brief  description  of  the  condition  of  animal 
and    plant   life.     Compare   with    September.     To    what 
cause  or  causes  are  the  differences  due  ? 

17.  Do  you  always  see  the  same  side  of  the  moon  ? 
By  means  of  a  globe,  sun,  and  moon,  explain. 

1 8.  Can  you  see  any  reason  for  believing  that  the  moon 
revolves  round  the  earth  ? 

19.  If  the  moon  revolves  round  the  earth  as  the  earth 
moves  through  its  orbit  round  the  sun,  can  you  tell  what 
kind  of  a  line  the  moon  must  describe? 

20.  Have  any  of  the  constellations  which  were  seen  last 
month  disappeared  ? 

In  addition  to  those  of  last  month  that  are  still  visible 
are  Auriga,  Orion,  and  Gemini. 


NORTH    AMERICA. 
Soil  and  Productions. 

1.  What  things  can  you  name  that  affect  the  fertility 
and  productiveness  of  soils  ? 

2.  Make  use  of  a  good  physical  relief  map  and  study 
the  conditions   which  affect  the  productiveness   of  the 
different  regions.     From  what  you   know  of  plant  life, 
what  are  the  primary  conditions  necessary  for  it. 

3.  Contrast  the  growth   and  general   appearance  of  a 
plant  during  a  wet  season  with  its  condition  during  a  dry 
one  ? 

4.  What  is  the  effect  of  heat  and  moisture   upon  the 
plants  that  you  have  noticed  ? 

5.  Use  a  map  which  shows  the  character  of  the  vege- 
tation in  different  regions  ;  what  climate  have  those  parts 
where  vegetation  is  most  luxuriant  ? 

6.  What  contrasts  in  the  products  of  the  Atlantic  and 
the  Pacific  coast  regions  ? 

7.  Compare  the  northern  half  with   the  southern  on 
each  coast ;  on  which  coast  is  the  contrast  greater  ? 

8.  In  the  great  central  plain,  contrast  the  eastern  and 
the  western    halves  ;  in  which    half  within  the  United 
States  ,are  the  productions  more  uniform  ? 

9.  In  which  half  do  the  agricultural  productions  extend 
farther  north  ? 

168 


December]  GEOGRAPHY.  169 

10.  Where  are  the  great  wheat-growing  regions  ?  How 
can    you    account    for    the     wheat-growing    region    of 
Texas,  since  a  similar  one  is   not  to  be  found   in  Mis- 
sissippi ? 

11.  Where  is  the  rice  production  greatest?     Contrast 
the  conditions  that  it  requires  with  those  necessary  for 
wheat. 

12.  Note   the   cotton-growing  region;    does  the  belt 
reach  the  Rocky  Mountains?     Can  you  see  a  reason  for 
this? 

13.  Contrast  the  corn-producing  regions   with    those 
mostly  devoted  to  wheat. 

14.  What  is  the  relation  of  the  tobacco  and  hemp  re- 
gions to  those  of  cotton  and  corn  ? 

15.  What  grains  flourish  in  a  cooler  climate  than  that 
best  adapted  .for  wheat  ? 

1 6.  Make  a  study  of  the  different  fruit  regions  ;  what 
part  of  the  continent  includes  the  greater  part  of  the 
fruit-growing  regions  ? 

17.  Compare  and  contrast  the  Atlantic  and  the  Pacific 
coasts.     What  are  the  staples  of  each  ? 

18.  Where  is  the  southern  boundary  of  the  apple  region? 
Where  is  the  chief  apple-growing  district  ? 

19.  What  effect,  if   any,   do   the   Great   Lakes  have 
upon   the   surrounding   country   in    the   production    of 
fruit  ? 

20.  What  climate  seems  best  suited  to  peach  raising? 

21.  What  is  best  adapted  for  oranges  ? 

22.  What   fruits  are   produced  south  of  the  United 
States  ?      What  ones  are  produced  north  of  the  United 
States? 

23.  Where  do  the  fruits  grow  farthest  north,  along  the 
coasts  or  in  the  interior  ? 


J7°  NATURE  STUDY.  [December 

Minerals. 

24.  From  what  parts  of  the  continent  are  the  minerals 
chiefly  obtained  ? 

25.  Contrast  the  eastern  and  western  highlands  as  to 
the  variety  and  kinds  of  minerals  produced. 

26.  Locate  the  iron  mines  that  are  now  being  worked 
most  extensively.     Where  are  the  copper  mines  ? 

27.  Where   are   the   bituminous   coal   regions  ?     The 
anthracite  coal  fields  ? 

28.  Where  are  the  gold  and  silver  mines  ?    The  mines 
of  quicksilver?     Of  lead  ? 

29.  Where  are  the  petroleum  deposits  ? 

30.  What  cities  are  the  chief  agricultural  depots  in 
the  north  ?     In  the  south  ? 

31.  What  are  the  chief  mining  cities?      What  is  the 
chief  coke  manufacturing  city  in  the  country  ? 

SOUTH  AMERICA.     CLIMATE. 

1.  Use  a  good   physical   map,  upon   which  the  ocean 
currents  and  winds  are  clearly  marked.     Model  the  map 
to  get  an  idea  of  the  climatic  effect  of  the  highlands, 
river  basins,  and  coast  lines. 

2.  How  does  the  latitude  of  South  America  affect  its 
climate  ?     Contrast  it  in  this  respect  with  North  America. 

3.  Contrast  the  area  of  South  America  that  lies  within 
the  tropics  with  that  of  North  America  in  the  correspond- 
ing latitude  ;  what  climatic  differences  must  be  due  to 
these  contrasts  ? 

4.  In  the  same  way  compare  the  temperate  regions  of 
the  two  continents. 

5.  What  climatic  difference  must  be  due  to  the  differ- 
ence in  the  character  of  the  coast  lines  of  the  two  conti- 
nents ? 


December]  GEOGRAPHY.  171 

6.  What  modification  of  the  climate  in  the  tropical  re- 
gions must  be  due  to  the  difference  in  relief  ? 

7.  How  does  the  position  of  the  great  Andean  highland 
affect  the  climate  within  the  tropics  ? 

8.  What  is  the  direction  of  the  prevailing  wind  within 
the  tropics  ?     What  must  be  its  character  as  to  moisture  ? 

9.  What  agencies  for  condensing  the  moisture  in  the 
northern  half  of  the  continent  ? 

10.  Contrast  the  western  slope  of  the  Andes  within  the 
tropics  with  the  eastern  ;    to  what  are  the  differences 
due  ? 

n.  What  do  the  rivers  indicate  as  to  the  amount  of 
moisture  east  of  the  Andes  ? 

12.  What  ocean  current  sweeps  the  eastern  shores  in 
the  temperate  regions?     Does  it  set  toward  or  away  from 
the  coast  ?     What  is  the  direction  of  the  wind  ? 

13.  What   ocean    current    skirts   the    western  coast  ? 
What  wind  west  of  the  mountains  ? 

14.  Contrast  the  southern  half  of  the  Pacific  coast  with 
the  northern  ;  what  causes  the  differences  ? 

15.  Contrast  and  account  for  the  differences  noted  be- 
tween the  eastern  and  the  western  coasts  of  the  southern 
half  of  the  continent. 

16.  Latitude  50°  north  or  south  is  noted  as  embracing 
regions  where  fogs  are  prevalent  ;  can  you  account  for 
this? 


During  the  winter  season,  opportunity  should  be  taken 
to  study  atmospheric  and  aqueous  agencies  that  are  con- 
stantly but  slowly  changing  the  face  of  the  earth  by  means 
of  frost  and  ice.  The  action  of  these  may  be  seen  and 
studied  on  a  large  scale,  if  one  has  a  chance  to  visit  a 
cliff,  a  river  shore,  a  pond  or  lake  beach,  and  quarries. 
One  or  more  of  these  can  hardly  fail  to  be  convenient  in 
almost  every  neighborhood,  and,  of  course,  whatever  is 
present  should  receive  the  larger  share  of  attention.  In 
lieu  of  a  cliff,  however,  a  stone  wall  will  sometimes  make 
a  good  substitute  ;  or,  what  is  generally  better,  the  bank 
of  some  ditch  will  show  how  the  water,  soaking  down  and 
then  freezing,  loosens  masses  of  earth  which  fall  off  and 
form  a  talus  at  the  bottom.  A  small  stream,  a  roadside 
brook  it  may  be,  will  often  show  exactly  how  a  river's 
banks  are  clutched  by  the  icy  fingers  which  sooner  or 
later  carry  away  masses  of  earth,  rock,  and  drift,  and  de- 
posit it  elsewhere.  The  ice  which  forms  under  a  cliff,  as 
will  be  illustrated  by  that  formed  along  any  steep  bank, 
receives  considerable  material  dropped  from  above,  which 
it  bears  away  when  thawed  loose  from  the  shore.  Some- 
times in  beds  of  finest  clay,  large  bowlders  are  to  be  found 
that  cannot  well  be  accounted  for,  except  on  the  suppo- 
sition that  they  were  dropped  by  floating  ice,  which 
doubtless  bore  them  to  the  spot  from  some  distant  place. 
When  the  ice  breaks  up  after  a  rain,  its  work  in  gouging 
and  cutting  the  banks  as  it  is  carried  along  by  the  cur- 


December]  GEOLOGY.  173 

rent  may  be  observed.  The  formation  of  ice  dams  or 
gorges,  and  their  subsequent  bursting  with  the  effects  of 
the  flood  which  follows,  may  also  be  noticed  in  any  stream, 
at  almost  any  sharp  curve,  or  where  some  obstruction 
chokes  the  channel. 

The  freezing  and  thawing  of  the  ground  is  also  an  in- 
teresting subject  for  observation  and  study.  The  freez- 
ing of  the  soil  uplifts  and  loosens  it,  so  that  erosion 
takes  place  more  easily.  By  the  uplifting  and  consequent 
settling  movements,  the  roots  of  grasses  and  other  plants 
are  sometimes  left  exposed,  and  are  then  killed.  On  hill- 
sides, the  effects  are  still  more  marked.  Water  falling  in 
hollows  above  stumps,  trees,  and  rocks,  by  its  alternate 
freezing  and  thawing  tends  to  push  such  objects  a  little 
farther  down  the  slope.  This  will  be  noticed  in  the  spring 
after  a  thaw,  when  trees  will  frequently  be  found  uprooted, 
and  rocks  will  be  moved  a  little  from  their  winter  bed. 

In  quarries,  or  where  rocks  have  been  long  exposed  to 
the  weather,  by  means  of  cracks  or  seams  of  softer  ma- 
terial which  has  been  washed  out,  water  finds  access  to  a 
greater  or  less  depth  below  the  surface.  When  frozen  it 
operates  with  great  force  in  splitting  the  rocks  apart. 

1.  Examine  the  ground  in  various  places  and  find  out 
something  as  to  the  depth  it  is  frozen.     Study  the  influ- 
ences which  cause  variation  in  the  depth. 

2.  Compare  places  near  a  building,  and  on  the  differ- 
ent sides  ;  on  which  side  is  it  frozen  deepest  ? 

3.  Find  a  place  where  the  ground  is  composed  of  clay  ; 
compare  the  depth  to  which  it  freezes  with  a  place  com- 
posed of  sand.     Compare  both  with  vegetable  mold  and 
loam.     What  precautions  must  you  observe  in  the  selec- 
tion of  places  of  observation,  that  your  results  may  be 
trustworthy  ? 


174  NATURE  STUDY.  [December 

4.  How  can  you  account  for  the  different  depths  fro- 
zen in  the  various  places  ? 

5.  Compare  a  piece  of  ground  covered  with  heavy  sod 
with  one  without  vegetation  ;  which  is  frozen  deeper  ? 

6.  What  difference  in  the  freezing  of  the  ground  under 
a  large  flat  stone  and  that  around  it  uncovered  ?     In  the 
same  way  examine  the  earth  under  a  board,  and  compare 
with  that  under  a  thin  stone. 

7.  Compare  wet  with  dry  places;  which  freeze  deeper 
and  the  sooner  ? 

8.  What  effect  does  a  forest  have  upon  the  freezing  of 
the  ground  ? 

9.  Compare   places   covered    with    snow    with   others 
where  the  snow  is  blown  away  ;  how  do  you  account  for 
the  different  depths  to  which  the  ground  is  frozen  ? 

10.  Does  vegetation  increase  or  diminish  the  possibil- 
ities of  the  soil  for  taking  up  water  ? 

11.  Does  the  depth  to  which  ground   freezes  seem  to 
depend  upon  the  water  it  soaks  up  ? 

12.  If  there   is  opportunity,  examine  a  freshly  plowed 
field  and  compare  it  with  one  that  has  settled  compactly. 

13.  Can  you  see  any  signs  of  weathering  away  of  the 
stones  in  the  walls  in  different  buildings? 

14.  Secure  specimens  of  the  different  kinds  of  stone, 
and  study  the  closeness  of  the  grain  in  each. 

15.  Can  you  see  a  cause  for  their  wearing  away  ?     Are 
there  any  cracks  or  seams  ? 

16.  Does   a   stone   freeze    through    like   a    lump    of 
earth  ? 

17.  When  broken,  can  you  find  any  frost  crystals  be- 
low the  surface  ? 

18.  Do  stones  take  up  water  like  the  soil  ?     To  test  this, 
dry  specimens  of  these,  taken   from  walls  and  elsewhere, 


December]  GEOLOGY.  175 

and  weigh  them  ;  then  soak  in  water  for  awhile,  dry  with 
a  cloth  as  much  as  possible,  and  weigh  again. 

19.  Which  ones  gained   most   weight?     How  do  they 
rank  as  to  durability  in  walls,  etc.  ? 

20.  Test  in  the  same  way  pieces  of  mortar  or  cement 
from  walls  or  pavements,  and  also  pieces  of  brick. 

21.  Compare  in  this   manner  different  kinds  of  stone, 
such  as  limestone,  marble,  flint,  granite,  sandstone,  and 
slate  ;  does  their  durability  correspond  in  any  way  to 
their  absorptive  powers  ? 


If  the  pupils,  during  the  preceding  months,  have  been 
reasonably  industrious  in  making  their  collections,  they 
will,  no  doubt,  have  found,  among  the  rest,  one  or  more 
varieties  of  iron  ore.  Good  examples  of  this  valuable  ore 
may  usually  be  picked  up  along  railroads  where  it  has 
been  dropped  from  passing  trains  laden  with  it.  If 
there  are  smelting  furnaces  near,  it  may  be  easily  ob- 
tained in  quantity,  and,  usually,  in  great  variety.  If 
possible,  also,  secure  good  specimens  of  pig  iron,  slag, 
rolled  bar,  cast  iron,  and  steel.  With  younger  pupils  a 
collection  of  tools,  utensils,  instruments,  etc.,  would  be 
valuable  in  illustrating  the  properties  of  each.  Sample 
sets  of  these  may  often  be  procured  from  manufacturers, 
who  are  almost  always  willing  to  furnish  them  to  any 
school  that  will  give  suitable  space  for  the  exhibit. 
Much  of  the  wall  space,  between  the  blackboard  and 
ceiling,  too  often  bare  and  unsightly,  may  well  be  given 
up  to  this  purpose.  Such  displays,  by  no  means  neces- 
sarily confined  to  this  one  subject,  will  often  be  used 
directly,  as  means  of  illustration  in  teaching  ;  and  in- 
directly,  by  their  constant  presence,  they  will,  in  many 
pupils,  stimulate  thought  and  impress  the  mind  with  some 
notion  of  the  useful  industries. 

The  richest  ores  from  which  iron  is  obtained  are  mag- 
netite, hematite,  and  limonite,  classed  as  oxides ;  and 
siderite  and  clay  iron-stone,  among  the  carbonates. 
For  specific  descriptions  of  these,  the  teacher  is  referred 


December]  MINERALOGY.  177 

to"  Crosby's  Tables  for  the  Determination  of  Minerals," 
a  copy  of  which  every  teacher  should  have,  and  to  Dana's 
Manual  of  Mineralogy.  The  latter  contains  a  brief  de- 
scription of  the  different  kinds. 

Pupils  are  generally  anxious  to  know  the  names  of  the 
different  minerals  that  they  find,  and  it  is  proper  that  the 
teacher  should  give  the  names  when  convinced  that  the 
questions  are  based  upon  something  higher  than  idle 
curiosity.  As  a  rule,  the  teacher  should  give  no  help 
until  sure  that  the  pupil  himself  has  invested  some 
thought  in  the  subject.  To  insure  this,  a  blank  form  for 
the  description  should  be  given  the  pupil,  to  be  filled 
out  from  his  own  study  of  the  mineral.  (See  Mineral- 
ogy for  September.)  When  this  has  been  done,  the 
teacher  may  then  give  the  name,  and  feel  fairly  as- 
sured that  he  is  helping  one  who  really  wishes  to 
know.  Of  course,  these  blanks  cannot  be  completely 
filled  until  the  preceding  lessons,  upon  the  physical 
characteristics  of  minerals,  have  been  given  and  under- 
stood. But  they  may  be  used  to  advantage  from  the  be- 
ginning, the  pupil  filling  them  out  as  the  work  proceeds. 
Simple  methods  of  making  the  tests  with  acids  and 
the  flame  are  described  in  this  book  under  the  head  of 
Mineralogy  in  the  work  outlined  for  January  and  April. 
The  teacher  is  referred,  also,  to  Crosby's  Tables,  or  any 
manual  of  determinative  mineralogy.  The  acid  test 
is  easily  made,  and  will  add  interest  from  the  start.  The 
flame  tests  should  not  be  attempted  until  the  pupils  are 
familiar  with  the  more  obvious  characteristics. 

1.  What  strongly  marked  characteristic  is  common  to 
all  iron  ores  ? 

2.  Find  the  specific  gravity  of  the  different  varieties  ; 
what  one  is  heaviest  ? 


178  NATURE  STUDY.  [December 

3.  Powder  a  small  piece  of  each  kind  and  test  with  the 
magnet  ;  which  is  most  strongly  magnetic  ?     Are  any  not 
attracted  at  all  ? 

4.  What  is  the  hardness  of  each  ? 

5.  What  is  the  difference  noticed  in  the  streak. 

6.  Compare  as  to  color  ;  what  color  distinguishes  the 
magnetite  ? 

7.  What  difference  in  shade  between  limonite  and  hem- 
atite ?     If   a  specimen  of  specular  iron   ore,  the   purest 
variety  of  hematite,  can  be  found,  it  will  be  recognized 
by  its  shining  mica-like  blades  with  a  metallic  luster. 

8.  Siderite,  iron  carbonate,  is  another  variety  less  rich 
in  iron  and  varying  much  in  its  appearance. 

9-.  Examine  specimens  of  pig  iron,  cast  iron,  wrought 
iron,  and  steel.  How  do  they  differ  in  appearance  ?  Can 
you  find  any  evidence  of  crystals  in  any  of  the  speci- 
mens ? 

10.  What  different  properties  do  they  possess? 

11.  Pig  iron  is  obtained  directly  from  the  ore  by  smelt- 
ing it  in  a  large  furnace  with  an  intense  heat.     The  ore 
is  mingled  with  broken  limestone  and  coal.     By  means 
of  a  hot  blast  the  iron  is  melted  out  and  settles  to  the 
bottom,    and  the  lighter  impurities  remain  on  the  top. 
At  intervals  the  melted  iron  is  drawn  off  into  a  number 
of  molds  formed   in   sand,   called    pigs.     This   process 
gives  the  crude  iron.     The  succeeding  processes,  pud- 
dling, hammering,  and  rolling,  are  designed  to  rid  it  of 
its  impurities  and  give  it  fiber  and  toughness. 

Cast  iron  articles  are  made  by  pouring  the  melted 
metal  into  molds  of  the  desired  form. 

12.  How  many  uses  can  you  name  for  cast  iron  ? 

13.  What  would  seem  to  be  its  most  useful  property  ? 

14.  Compare  it  in  appearance  with  cast  steel  ? 


December]  MINERALOGY.  1 79 

15.  What  useful  articles  are  made  from  steel  ?     What 
are  its  valuable  properties  ?     A  most  useful  character- 
istic of  steel  is  that  it  may  be  so  treated  as  to  have  dif- 
ferent degrees  of  hardness  and  elasticity.     Take  a  fine 
steel  knitting-needle  and  bend  it.     On  being  released  it 
regains  its  former  shape  by  its  elasticity.      Heat  to  red- 
ness and  plunge  into  cold  water,  and  it  will  become  hard 
and  brittle  and  break  easily.     Heat  again  and  allow  it 
to  cool  slowly,  and  it  becomes  softer.     The   process  of 
reheating  and  cooling  of  steel  is  called  tempering,  and  by 
it  many  different  degrees  of  hardness  and  elasticity  are 
obtained. 

16.  What  are  the  chief  uses  of  rolled  iron  ?      How 
does  a  freshly  broken  surface  differ  in  appearance  from 
that  of  cast  iron  or  steel. 

17.  What  are  its  most  useful  properties. 


Zoology 

GENERAL    OBSERVATIONS. 

1.  What   animals   are   you    sure     must    remain   over 
winter  with  us  that  are  not  to  be  found  abroad  ? 

2.  Why  do  not    all  animals    migrate  ?     Is  it  due   to 
superior  or  to  less  intelligence,  or  to  neither  ? 

3.  What  animals  that  you  are  sure  must  remain  here 
during  the  winter  provide  themselves  beforehand  with  a 
supply  of  food  ?     Will   such  animals  lay  up  a  store  of 
food  when  kept  as  pets  ?     How  do  you  explain  this  ? 

4.  What  is  the  character  of  the  food  with  which  they 
supply  themselves  ? 

5.  Where  do  such  animals  usually  stay  ? 

6.  Are  there  any  that  do  not  lay  up  a  store  of  food 
which  live  through  the  winter  ? 

7.  Where  do  such  animals  live  ? 

8.  Can  you  see  any  reason  why  all  animals  do  not  store 
food  for  winter  use  ? 

9.  Does  the  activity  of  animals  vary  with  the  season  ? 
Is  it  economical  for  them  to  remain  in  a  state  of  rest  at 
certain  times  ? 

10.  What  animals  that  remain  here  during  the  winter 
are  active  ?  What  is  their  food  ? 

u.  Do  you  see  any  relation  between  the  activity  of  an 
animal  and  its  food  supply  ? 

12.  Do  animals  which  remain  quiet  during  the  winter 
take  precautions  against  the  cold  ? 

180 


January]  ZOOLOGY.  181 

FOODS.     DIFFERENT  KINDS. 

1.  Do  you  notice  any  difference  between  your  summer 
and  winter  diet  ? 

2.  Compare  closely  the  character  of  the  food  which 
makes  up  a  meal  in  January  with  that  of  a  meal  in  July. 
What  articles  especially  relished  in  July  that  are  omitted 
now  ? 

3.  Does  the  character  of  the  food  vary  with  the  occu- 
pation ?     Contrast  the  diet  of  a  man  who  does  physical 
labor  with  that  of  a  book-keeper.     Does  your  own  desire 
for  particular  foods  vary  with  the  kind  of  work  you  do  ? 

4.  What   influences  affect  the  amount  of    food    you 
take? 

5.  Can  you  notice  any  change  in  your  weight  at  differ- 
ent times?     How   can    you   account  for  your  losing    in 
weight  at  times  and  for  your  gaining  at  others  ? 

6.  From  your  own    observations,  what  different  uses 
can  you  see  for  food  ? 

7.  What  means  have  you  of  knowing  whether  an  article 
is  fit    for  food  or  not  ?     How   does   the  nose  assist  in 
making  selection  ? 

8.  Is  the  taste  assisted  by  the  sense  of  smell  ?     Close 
the  eyes  and  hold  the   nostrils,  and  try  distinguishing 
different  articles  of  food  by  tasting  them. 

9.  What  parts  of  the  mouth  are  concerned  in  tasting  ? 
Try  touching  different  substances  to  the  tip  and  back 
part  of  the  tongue,  to  the  inside  of  the  cheek,  to  the 
gums,  to  the  under  side  of  the  tongue.     Where  is  the 
sense  of  taste  most  acute  ? 

10.  Is   the    same   part   equally   sensitive  to    different 
substances  ?      Try  sour,   sweet,   and   bitter    articles  to 
different  points  of  the  tongue. 


182  NATURE  STUDY,  [January 

11.  By  means  of  a  mirror  and   a  good  light  observe 
carefully  the  surface  of  the  tongue  ;  note  the  roughness 
and  the  small  individual  elevations  which  cause  it.     Com- 
pare with  the  tongues  of  the  dog  and  the  cat. 

12.  These  elevations  are  called  papillae.     The  smallest 
in  size  are  the  filiform  papillae,  and  the  less  numerous 
but   larger   rounded    dots    are   the    fungiform   papillae. 
Draw  the  tongue  well  forward  and  press  it  down  with  a 
spoon  handle  and  notice  a  V-shaped  row  on  the  back 
part  ;  these  are  the  circumvallate  papillae.     The  papillae 
aid  in  giving  us  the  taste  of  food. 

13.  Do  all  articles  give  us  the  sense  of  taste  ?     Mention 
those  easily  tasted.     Mention  some  that  have  little  or  no 
taste.     Can  you  taste  a  stone  ?     Salt  ?     What  causes  the 
difference? 

14.  Can  the  acuteness  of  taste  be  cultivated  ?     With 
whom  is  tasting  a  business  ? 

15.  What  influences  our  likes  and  dislikes  of  certain 
tastes?     Do    young   children   sharply    discriminate    by 
taste  ? 

16.  What  distinction  is  there  between  gratifying  taste 
and  satisfying    the  appetite  ?     Is   the  taste  as  acute  at 
the  end  of  a  meal  as  it  was  at  the  beginning  of  it  ? 

17.  Are  foods  that  are  the  most  pleasant  to  the  taste, 
the  staple  articles  of  diet  ? 

1 8.  What   seems    to    be    the   use    of    the    sense    of 
taste  ? 

19.  Do  all  the  animals  that  you  know  of  have  the  sense 
of  taste  ?     Of  what  use  would  it  be  to  grain-eating  birds? 
Do  the  dry  seeds  differ  in  taste  ?     How  do  birds  find 
out  what  kind  of  seeds  they  want  ? 

20.  Do  the  brute  animals  determine  whether  or  not 
an  article  is  fit  for  food  by  tasting  ? 


January]  ZOOLOGY.  l§3 

COOKING. 

1.  Can  you   see  any  good  reason  for  cooking  food  ? 
In  what  way  does  it  change  meat  ? 

2.  Does  the  taste  we  get  from  a  piece  of  meat  depend 
upon  the  way  in  which  it  was  cooked  ? 

3.  The  art  of  cooking  is  based  upon  a  few  simple  prin- 
ciples, which   are   determined   by  certain   characteristic 
properties  of  the  different  food-stuffs,  and  which  are  ex- 
hibited when  brought  into  contact  with  heat.     The  prin- 
ciples are  easily  understood,  and  the  facts  may  soon  be 
learned,  but   to  become  an  expert   in  this  most  useful 
art  nothing   will    take   the    place    of   long    and    patient 
practice. 

4.  Put  a  small  amount  of  the  white  of  an  egg  in  a  test 
tube,  and  subject  it  to  a  sudden  and  strong  heat  ;  what 
change  does  it  undergo  ? 

5.  Try  again,  but  let  the  heat  be  very   moderate,  not 
enough  to  cook  it  ;  does  it  undergo  change  ? 

6.  Put  a  little  more  of  the  white  of  an  egg  into  a  tube 
or   bottle,   and    pour    boiling    water    upon  it  ;  note    the 
change.     Try  again,  and  use  slightly  warm  water  ;  what 
difference  in  the  results  ? 

7.  The  principal   substance  of  lean   meat  is  similar  in 
its  properties  to  the  white  of  an  egg.     Now  suppose  you 
wished  to  roast  meat  ;  is  it  desirable  to  keep  the  juices 
within   the  meat,  or  should  they  be  allowed  to  escape 
into  the  pan  ? 

8.  Which   would  you  advise  at  first,  a  quick  or  slow 
heat  ?     Why? 

9.  In  boiling  meat,  would  you  put  it  into  hot  or  cold 
water  at  the  start  ?     Why  ?     How  would  it  be  if  you 
wished  to  make  soup  ? 


1 84  NATURE  STUDY.  [January 

10.  In   frying  meat,   should  the  pan  be  hot  or  cold 
when  the  meat  is  put  into  it  ?     Why  ? 

11.  Why  is  broiled  meat  usually  juicy? 

12.  Many  vegetables,  such  as  beans,  peas,  and  pota- 
toes, are  rich  in  starch,  which   when  cooked   swells  up 
and  becomes  dry  and  mealy.     In  this  condition  it   is 
more    easily   digested   than    it   is   when    in    a  compact 
mass. 

13.  Obtain  a  little  wheat  and  dry  it ;  when  well  dried 
pound  or  grind  it  up  very  fine  in  a  mortar.     Add  a  little 
water  and  stir  well. 

14.  Note  the  tenacity  of  the  dough  thus  formed.     It 
is  due  to  a  substance  called  gluten,  which  is  the  most  nu- 
tritious part  of  the  grain.     Starch  is  also  present.     The 
bran  is  rich  in  mineral  constituents. 

15.  Take  a  lesson  at  home  in  bread  making,  and  write 
a  description  of  the  process. 

16.  At  what  point  is  the  yeast  added?     Why  knead 
the  dough? 

17.  What  is  the  use  of  the  yeast  ?     Recall  the  lessons 
on  fermentation.     Why   does  bread   sometimes  sour  be- 
fore it  is  baked  ?     Why  must  it  be  kept  warm  while  ris- 
ing ? 

1 8.  Why  bake  the  bread  ?     Why  is  baked  bread  full  of 
little  cavities  ?     Why  is  fresh  bread   less  healthful  than 
dry  bread  -? 

HUNGER  AND  APPETITE. 

1.  How  does  the  character  of  one's  occupation  affect 
his  appetite  ? 

2.  What  seems  to  be  essential  for  a  regular  appetite  ? 

3.  What  seems  to  be  the  function  or  use  of  the  feel- 
ing of  hunger  ? 


January]  ZOOLOGY.  185 

4.  Does  the  character  of  the  occupation,  mental  or  phys- 
ical,   affect  the   location  of  the  feeling  ?     The  demand 
for  more  work  material  in  the  brain  worker  as  well  as  in 
the  muscle   worker  is  made  through  the  appropriate  or- 
gan in  the  feeling  of  hunger.     We  never  are  hungry  in 
either  our  heads  or  our  hands  ;  both  of  these  parts  refer 
their  wants  to  certain  parts  of  the  alimentary  canal,  the 
organ  that  shall  speak  for  them. 

5.  Is   the  feeling  of  hunger,   if  not    satisfied,  a  per- 
sistent one  ? 

6.  If  the   hunger  of  a  brain  worker   is  not  satisfied 
when  it  occurs,  what  feelings  are  likely  to  follow  ?     What 
feelings  in  the  case  of  the  muscle  worker  ? 

7.  What  do  these  feelings  which  succeed  hunger  indi- 
cate as  to  the  effect  of  labor  upon  the  body  ? 

8.  At  what  time  is  the  appetite  sharpest  ?     When  is  it 
least  ? 

9.  If  you  retire  at  night  hungry,  are  you  hungry  when 
you  awake  ?     Why  is  this  ? 

10.  Are   there   any  emotions   or    external    conditions 
which  tend  to  abate  the  feelings  of  hunger  ? 

11.  Are  there  any  external  conditions  which  tend  to 
increase  the  feelings  ? 

12.  How  is   one  to   know  when  he  has  taken   enough 
food  ?     If  the  meal  be  an  agreeable  and  an  uninterrupted 
one,  the  loss  of  the    hungry  feeling   may,   perhaps,  be 
taken  as  a  guide  to  the  amount  of  food  that  should  be 
eaten.     But  it  is  possible  for  the  pangs  of  hunger  to  be 
satisfied  by  a  greatly  insufficient   amount   of  food,  as 
any  one  can  testify  who  has  been  called  away  from  a  meal 
before  he  has  eaten  the  usual  amount.     On  returning  the 
feeling  of  hunger  is  generally  entirely  gone  ;  but  that 
there  was  an  insufficient  amount   of  food  is   shown  by 


1 86  NATURE  STUDY.  [January 

the  subsequent  feelings  which  come  when  work  is  re- 
sumed. It  would  seem  that  the  feelings  of  hunger  can- 
not accompany  the  work  of  digestion  ;  if  any  food  is 
taken  into  the  stomach,  no  matter  how  small  in  amount, 
and  there  is  a  pause  in  the  meal,  digestion  begins  and 
hunger  is  no  longer  felt. 

13.  What  have  you  noticed  about  the  habits  of  differ- 
ent animals  after  they  have  taken  food  ?     Notice  the  dog, 
cat,  horses,  and  cattle.     Are  they  active  or  do  they  rest? 
How  is  it  with  a  baby  ? 

14.  How  do  your  own  inclinations  and  feelings  change 
after  a  full  meal  ?     Can  you  account  for  this  ? 

15.  Do  domesticated  and  wild  animals  seem  to  observe 
any  regularity  in  their  times  of  taking  food  ?     Observe 
the  dog  and   the    cat.     When   cattle   are  left  quietly    to 
themselves,  with  good  pasturage,  they  feed  with  tolerable 
regularity  about    four   times    a  day.     They    begin    very 
early  in  the  morning,  and  feed  for  an  hour  or  two  ;  and 
then,  if  the  day  be  warm,  they  seek  the  shade  or  a  stream. 
Before  noon  they  sally  forth  again  to  graze  and  then  they 
spend  the  heated  noontide  in  the  shade.     Another  meal 
in   the   afternoon  is    followed    by  a  drowsy  rest  in  the 
shade  ;  then  a  full  supper  as  the  sun  goes  down  brings 
their  day  to  a  close. 

16.  Can  you  see  anything  in  the  habits  of  animals  or 
in  the  nature  of  their   food  which   affects  the  periods  of 
their  eating  ?     Does  the  age   of    the  animal   have   any 

"effect  ? 

17.  How  do  you  account  for  the   fact  that  many  peo- 
ple  eat  but  twice  a   day  ?     In  considering  this  question 
account  should  be  taken  of  the   habits  and   occupations 
of  the  individuals. 

18.  Under  what  conditions  is  it  better  to  have  a  light- 


January]  ZOOLOGY.  187 

lunch  at  midday  and  a  full  meal  in  the  evening  ?     When 
the  reverse  ? 

19.  Do  you  know  by  experience  of  any  ill  effects  from 
taking  a  full  meal  of  good  food   just  before  retiring   at 
night  ? 

20.  What  reasons  can  you  suggest  for  the    regular  re- 
currence of  the  times  at  which  food  is  taken  by  animals  ? 

BOOK   FOR  REFERENCE.     Humboldt  Library,  No.  48,  Life  in   Na- 
ture.    Chapters  on  Nutrition. 


Botany 


During  the  winter  occasional  observations  should  be 
made  upon  plants,  and  the  effects  of  frost  and  freezing 
may  be  noted.  The  phenomena  of  growth  are  perhaps 
entirely  absent,  though  in  particularly  mild  winters  it  is 
not  unusual  to  find  dandelions  in  full  bloom  at  this  time. 
A  very  few  days  of  mild  weather  in  midwinter  will  be 
sufficient  to  coax  the  chickweed,  in  sheltered  places,  to 
spread  out  its  delicate  petals.  But  for  most  part,  plants 
seem  to  understand  the  treachery  of  these  exceptional 
warm  periods,  and  refuse  to  pay  them  any  heed. 

1.  Can  you  find  any  buds  that  have  been  killed  by  the 
frost?     Collect  a  large  number  and  get  the  percentage 
killed. 

2.  Where  are  the  living  parts  of  the  buds? 

3.  Do  the  central  parts  of  the  buds  freeze  ? 

4.  What  can  you  find  about  the  buds  that  acts  as  a 
protection  against  frost  ? 

5.  Do  any  birds  or  other  animals  use  the  buds  for 
food  ? 

6.  In  what  condition  are  the  acorns  and  other  nuts 
that  may  be  found  at  this  time  ? 

7.  Can  you  find  any  seeds   that   have   sprouted   and 
afterward  have  been  killed  ? 

8.  Have  the  nuts  and   seeds  that  are  covered   with 
fallen  leaves  been  frozen  ? 

9.  Is  there  any  sap  between  the  bark  and  the  wood  ? 

10.  Is  there   any  moisture   in  the   wood  ?     Does  the 
water  in  the  twig  freeze  ? 


AIR. 

There  are  few  experiments  requiring  simpler  apparatus 
than  those  which  will  well  illustrate  many  facts  and 
phenomena  relating  to  air  ;  and  it  may  be  added,  there 
are  few  possessing  greater  attraction,  or  that  are  more 
useful  in  explaining  many  interesting  phenomena  daily 
observed.  From  the  simplicity  of  the  apparatus,  how- 
ever, and  the  common  occurrence  of  the  phenomena  due 
to  air  pressure,  etc.,  it  must  not  be  imagined  that  the 
conception  of  the  real  character  of  air  is  one  easily 
gained.  The  fact  that  the  air  is  invisible  renders  its 
study  difficult  and  stands  in  the  pupil's  way  of  getting  a 
definite  idea  of  what  it  really  is.  Some  things  indeed 
seem  to  lead  straight  to  a  misconception  ;  for  example, 
since  it  floats  above  the  surface  of  the  earth,  the  ordinary 
experience  of  the  child  leads  him  to  believe  that  it  is 
without  weight.  It  will  be  found  that  very  few  pupils  in 
grammar  schools  associate  the  rising  of  water  in  a  tube 
"  by  suction  "  with  air  pressure  outside,  which  is  its  true 
cause.  They  almost  invariably  have  the  notion  that 
there  is  some  mysterious  kind  of  pulling  power  inside 
the  tube.  The  experiments,  therefore,  which  will  assist 
"in  giving  the  correct  idea,  should  be  repeated  and  ex- 
tended until  the  pupils  have  the  conception  that  the 
rising  of  a  liquid  in  the  tube,  and  in  all  similar  instances, 


19°  NATURE  STUDY.  [January 

is  due  to  an  unbalanced  pressure.  The  explanation  of 
why  water  will  rise  in  a  pump  stock  is  really  as  simple 
as  the  one  necessary  to  show  why  one  end  of  a  see-saw 
goes  up  if  only  one  person  is  on  the  board.  The  only 
reason  why  the  former  is  not  understood  as  well  as  the 
latter  is  because  of  the  difficulty  in  conceiving  that  the 
air  has  weight. 

Elasticity  of  Air. 

1.  Fill  a  small  bottle  half  full  of  water.     Through  the 
cork  pass  a  small,  tightly  fitting  glass  tube,  which  should 
reach  to  the  bottom  of  the  water.     If  the  cork  is  not  air- 
tight, cover  with    wax.      (See    Chemistry  for  January.) 
If  the  tube  is  drawn  to  a  fine  point  at  the  upper  end,  the 
experiment  will  be  more  interesting. 

2.  Blow  strongly  through  the  tube  into  the  bottle  and 
quickly  remove  the  end   of  the  tube  from  the  mouth  ; 
explain  what  you  observe. 

3.  What  occupies  the  space  in  the  bottle  above  the 
water  before  blowing  into  it  ?    Why  is  it  possible  to  blow 
air  into  the  bottle  ? 

4.  Does  the  air  which  was  blown  into  the  bottle  escape 
again  ? 

5.  Is  the  water  all   driven   from  the   bottle  ?     Upon 
what  does  the  amount  which  escapes  depend  ? 

6.  Can  you  explain  why  the  water  is  not  driven  out  of 
the  bottle  by  the  air  already  there  before  blowing  into  it? 

7.  Can  you  think  of  any  solid  body  which  the  action 
of  the  air  in  the  space  above  the  water  resembles  ? 

8.  Remove  the  cork  and  invert  the  bottle  in  a  small 
basin  or  cup  of  water  ;  does  the  water  enter  the  bottle? 
Why  ? 

9.  Push  the  bottle,  month  downward,  into  the  vessel  of 
water  ;  does  the  water  fill  the  bottle  ?     Why  ? 


January]  PHYSICS.  19 l 

10.  Pass  a  small  funnel  through  the  cork  and  connect 
it  tightly  with  wax  ;  press  tightly  into  the  bottle  and  fill 
the  funnel  with  water.  Can  you  fill  the  bottle  with 
water  in  this  way  ?  Why  ?  Try  filling  the  bottle  when 
the  funnel  fits  loosely  in  the  mouth  of  the  bottle. 

Pressure  of  Air. 

1.  Warm  giadually  a  test  tube  or  bottle  in  the  flame 
of  the  alcohol  lamp,  invert  it,  and  press  it  closely  upon 
the  back  of  the  hand  ;  as  it  becomes  cool,  what  do  you 
observe  ? 

2.  Was  the  bottle  or  test  tube  entirely  empty  before  it 
was  heated  ?     What  was  accomplished  by  warming  it? 
Recall  an  experiment  performed  in  Physics  in  the  Novem- 
ber work  to  explain  this. 

3.  What    must    have    taken    place    when    the   bottle 
cooled  ? 

4.  Hold  the  arm  in  different  positions  ;  does  the  bottle 
still  cling  to  it? 

5.  Remove  the  bottle  (noting  any  sound  made  as  it 
is  pulled  away)  and  heat  it  again  ;  invert  it  over  a  saucer 
of  water  with  the  mouth  below  the  surface. 

6.  As  it  cools,  what  takes  place?     How  does  it  differ 
from  what  happens  when  a  cool  bottle  is  so  inverted  in 
water  ? 

7.  Boil  an  egg  until  hard  and  remove  the  shell  ;    heat 
as  above,  or  by  dropping  a  lighted  taper  into  it,  a  bottle 
with  a  mouth  somewhat  too  small  to  allow  the  egg  to 
pass  through  readily.     Moisten  the  edge  of  the  opening, 
and  when  quite  hot,  quickly  place  the  egg  in  it,  the  small 
end  down. 

8.  Consider  what  takes  place  as  the  bottle  cools.     If 
the  opening  is  of  the  proper  size  the  egg  will  pass  into 


192  NATURE  STUDY.  [January 

the  bottle.  By  recalling  previous  experiments  (see 
Physics  for  November),  devise  an  easy  means  of  getting 
the  egg  out  of  the  bottle  without  injury  to  either. 

9.  Bend  a  glass  tube,  the  size  of  a  lead  pencil,  into 
something  like  a  U-shape  so  that  each  arm  shall  be  three 
or  four  inches  long.     Immerse  completely  in  water  until 
filled.     Fit  a  piston,  made  by  wrapping  a  greased  string 
or  strip  of  cloth  around  a  stick  or  wire,  into  one  end  of 
the  tube,  and  push  it  half-way  down  the  arm  and  then 
partially  withdraw  it.     Watch  the  water  in  the  tube. 

10.  Repeat   the  experiment,  holding  the  tube  in  dif- 
ferent positions — upside  down,  horizontal,  etc. 

11.  Hold  the  tube  upright,  and  push  the  piston  down 
half-way  ;  see  that  the  other  arm  of  the  tube  stands  level 
full  of  water.     Place  a  finger  tightly  over  this  end  and 
slowly  withdraw  the  piston.     Does  the  water  follow  the 
piston  ?     Remove  the  finger  and  note  the  result.     In  this 
exercise  note  whether  or  not  the  piston  is  air-tight  ;  how 
can  you  find  this  out  ? 

12.  Repeat  the  experiment  suggested  in  (n),and  with- 
draw the  piston  entirely  from  the  tube  ;  can  you  account 
for  what  takes  place  ? 

13.  Place  a  small  tube  of  any  kind  between  the  lips, 
and,  with   the  finger  over  the  other  end,  suck  the  air 
from  it  and  apply  the  tongue  to  the  end  ;  what  takes 
place  ?     Remove  the  finger  and  note  the  difference. 

14.  Close  the  lips  and   try   drawing  or  sucking  the 
cheeks  in  between  the  teeth  ;  when  well  drawn  in,  what 
is  the  effect  of  slightly  opening  the  lips  ? 

15.  Using  the  tube  mentioned  in  (9),  immerse  it  partly 
in  an  upright  position  in  water  ;  does  the  water  rise  in 
it?     Lift  it  out  of  the  water  slowly,  and  watch  the  water 
inside  the  tube. 


January]  PHYSICS.  193 

1 6.  Immerse  it  again  in  the  same  way,  close  the  upper 
end  tightly  with  the  finger,  and  remove  from  the  water  ; 
what  difference   do  you  see  ?     Remove  the  finger  and 
notice  what  takes  place. 

17.  Fill  a  large  bottle  with  a  small  opening  level  full 
and   invert  it;    does  the  water   run   out?     If  a  small- 
necked  bottle  cannot  be  obtained,  get  one  with  a  good 
cork,  through  which  a  small  hole  may  be  drilled. 

1 8.  Sink   a  bottle  or  a  tube  below  the  surface  in  a 
vessel  of  water,  and  let  it  lie  on  its  side  until  it  is  com- 
pletely filled  ;  turn  it  up  mouth  downward,  and  raise  it 
so  that  the  mouth  is  just  below  the  surface.     Is  there  any 
water  still  in  the  bottle  ? 

19.  Can  you  give  any  reasons  for  what  has  taken  place 
in  the  foregoing  experiments  ?     In  the  first  one  did  the 
bottle  make  any  mark  upon  the  hand  ? '  How  could  you 
make  such  a  mark  with  the  bottle  without  first   heating 
it  ?     Try  pressing  the  bottle  firmly  against  the  hand  for 
some  time. 

20.  Why  does  heating  the  bottle  first  enable  the  water 
to  rise  in  it,  as  in  (6),  when  it  does  not  do  so  as  in  (8) 
under  elasticity  ? 

21.  Is  the  water  drawn  up  into  the  bottle,  or  is  it 
pushed  into  it  ?     Is  there  anything  inside  to  draw  it  ?     Is 
there  anything  outside  to  push  it  ? 

22.  Is  the  egg  in  (7)  drawn  into  the  bottle  or  pushed 
into  it  ?     What  is  there  to  draw  or  push  ? 

23.  Can  you  make  the  air  in  the  bottle  push  the  egg 
out  again  ? 

24.  When  the  piston   is  pushed  down   in  (9),  is  the 
water  pushed  or  drawn  out  of  the  opposite  end  ? 

25.  While  the  piston  is  being  withdrawn,  is  the  water 
when  following  it  being  pushed  or  drawn? 


194  NATURE  STUDY.  [January 

26.  Does  the  water  refuse  to  follow  the  piston  in  (n) 
while  the  finger  remains  on   the  opening  in   the  tube? 
Has  the  piston  any  means  of  drawing  it  ?     If  the  piston 
is  not  air-tight,  how  will  it  affect  the  results  ? 

27.  If  possible,  procure  a  thick  glass  tube  thirty  inches 
long  having  a  bore  of  about  one-fourth  of  an  inch,  and 
also  a  small  bottle  of  mercury.     Stop  one  end  of  the 
tube  and  by  means  of  a  small  funnel  fill  it  with  mercury. 
Place  the  thumb  over  the  upper  end,  and  then  invert  in 
a  small  cup  of  mercury.     Does  the  mercury  run   out? 
Measure  the  height  of  the  column.       If  a  barometer  be 
at  hand  compare  the  height  of  the  mercury  in  the  tube 
with  it. 

28.  Repeat    the  experiment,  using   water    instead    of 
mercury.     What  difference  between  the  water  and  the 
mercury  ?     Mercury  is  thirteen  and  a  half  times  as  heavy 
as  water  :  how  high  a  column  of  water  would  be  sustained 
by  a  pressure  equal  to  that  in  (26)  ? 

29.  What    force  holds  these  fluids    up    in    the   tube  ? 
Explain  how  the  same  force  has  acted  in  previous  exer- 
cises. 

30.  What  use  can  you  see  for  the  barometer?     Why 
does  the  mercury  sometimes  stand  higher  than  at  others 
in  the  barometer? 

31.  Why  must  the  barometer  tube  be  closed  at   the 
upper  end  ?     Is  there  air  in  the  space  above  the  mer- 
cury ?     Why  ? 

32.  Why  is  it  that  the  mercury  of  the  barometer  enables 
us  to  measure  the  pressure  of  the  air  and  that  in  a  ther- 
mometer measures  temperature  ? 

33.  From  the   foregoing   experiments  can  you  tell  in 
what  directions  air  presses  ? 

34.  The  actual  pressure  of  the   atmosphere   is  about 


January]  PHYSICS.  195 

fifteen  pounds  to  each  square  inch  of  surface  ;  calculate 
the  pressure  on  top  of  a  desk  ;  of  a  table  ;  on  the  floor 
of  a  room.  Why  does  not  this  great  weight  crush  every- 
thing beneath  it  ? 

35.  Why  are  our  bodies  not  crushed  by  this  weight, 
which  on  an  average-sized  man  equals  twenty  tons  ? 
How  does  it  affect  people  who  ascend  to  great  heights 
in  balloons  ?.  Can  you  account  for  this  ? 

THE    PENDULUM. 

To  follow  the  work  on  the  equilibrium  of  bodies 
planned  for  the  previous  month,  an  interesting  series  of 
observations  and  experiments  may  be  made  with  the 
pendulum.  They  will  afford  fine  opportunity  for  the 
pupils  to  develop  skill  in  making  and  delicacy  in  manip- 
ulation. 

1.  Suspend  from  any  convenient  support  a  large  bullet 
by  means  of  a  small  thread,  two  feet  long  ;   when  the 
bullet  is  drawn  a  little  to  one  side  of  its  position  of  rest, 
can  you  see  why  it  swings  ? 

2.  What   kind   of   a    path   does    the   ball   describe   in 
swinging?     It  is  called  an  arc.     When  the  ball  is  at  one 
extremity  of  the  arc,  what  two  forces  are  acting  upon  it? 
Note  carefully  the  line  of  direction  of  each  force.    Com- 
pare with  these  two  lines  the  direction  through  which 
the  ball  really  moves  at  each  point  in  the  arc.     Why 
does  the  pendulum  begin  to  swing  in  the  opposite  direc- 
tion ? 

3.  An  oscillation  or  vibration  is  the  motion  from  one 
extremity  of  the  arc  to  the  other.     The  angle  measured 
by  the  arc   is   the  amplitude  of  vibration.     The  time  it 
takes  the  ball  to  move  through  this  arc  is  the  time  of 
vibration. 


J96  NATURE  STUDY.  [January 

4.  Swing  the  pendulum  through  a  short  arc  and  note 
the  number  of  vibrations  to  a  minute.     Vary  the  experi- 
ment, making  the  arc  longer  and  shorter,  and  count  the 
vibrations  per  minute  ;    what  fact  do  you  learn  ? 

5.  Make  another  pendulum  of  same  length,  but  use  a 
cork  ball  of  same  size  as  the  bullet.     Compare  the  oscil- 
lations of  the  two  pendulums. 

6.  Suspend  another  bullet  by  a  shorter  thread  ;    how 
do  its  oscillations  compare  with  the  first  one  made  ? 

7.  How  long  must  it  be  so  that  it  will  vibrate  just 
twice  as  fast  ?     Compare  the  length  of  the  two. 

8.  What  do  you  notice  about  the  times  of  vibration  and 
the  number  of  vibrations  in  a  given  time  of  the  two  pen- 
dulums ?     Try  those  of  other  lengths. 

9.  Can   you   make  one  which   will   vibrate  seconds  ? 
How  long  is  it  ?    What  does  the  pendulum  of  your  clock 
at  home  vibrate  ? 

10.  What  advantage  in  using  the  pendulum  in  meas- 
uring time  ?     What  is  the  use  of  the  spring  or  weights 
and  the  other  parts  of  a  clock  ? 

11.  What  means  were  used  for  measuring  time  before 
clocks  were  invented  ? 

12.  Suppose  a  clock  runs  too  fast,  how  can  you  prop- 
erly regulate  it  ?    Why  ?    Why  do  the  extremes  of  winter 
and  summer  affect  the  running  of  a  clock  ? 

13.  Suspend  bars  of  wood  having  same  length,  but  of 
different  shapes,  such  as  conical,  one  suspended  by  the 
base  and  the  other  by  the  apex,  prismatic,  spindle-shaped, 
etc.,  and  observe  the  oscillations  of  each  ;    can  you  ac- 
count for  the  variations? 

14.  Which  is  really  the  longest  pendulum  mentioned 
in  (13)?     Which  the  shortest  ?     How  can  you  decide  ? 


Chemistry 


HYDROGEN. 

In  making  hydrogen,  and  performing  experiments 
with  it,  the  pupils  should  follow  with  great  care  all  the 
directions  given.  It  is  easier  and  much  better  to  pre- 
vent an  accident  in  laboratory  work  than  it  is  to  repair 
the  mischief  done  by  one.  The  pupils  should  be  trained 
to  make  themselves  certain  of  each  step  in  any  process 
before  taking  it.  When  hydrogen  is  tningled  with  air  or 
with  oxygen,  the  mixture  is  explosive.  Upon  this  fact  are 
based  all  the  precautions  necessary  to  be  observed  in  the 
making  of  hydrogen,  and  in  its  management  in  the  fol- 
lowing exercises.  With  this  single  point  in  mind,  it 
is  easy  and  practicable  for  pupils  to  perform  a  num- 
ber of  interesting  and  profitable  experiments.  It  is 
doubtful,  however,  if  it  be  advisable  for  the  teacher  to 
undertake  such  a  course  of  experiments  when  the  pupils 
cannot  do  all  or  the  essential  part  of  the  work  for  them- 
selves. It  should  be  planned  to  have  the  pupils  do.  It 
is  not  denied  that  they  may  be  instructed  by  what 
they  see  and  hear  the  teacher  do  ;  but  there  is  so  much 
that  the  pupils  can  do  for  themselves,  and  the  power  they 
gain  by  doing,  by  working  out  patiently  all  the  details  for 
themselves,  is  so  much  greater,  that  it  is  nothing  less  than 
depriving  them  of  their  rights  to  fail  in  meeting  their 
capabilities  for  work.  Teachers  are  as  far  astray  when 

197 


198  NATURE  STUDY.  [January 

they  do  what  the  pupils  should  do,  as  they  are  when  they 
assume  to  think  for  them. 

Materials  Needed. 

1.  Procure  a  wide-mouthed  bottle,  holding  two  to  four 
ounces,  for  each  pupil.    Fit  a  piece  of  glass  tubing,  three 
or  four  inches  long,  through  the  cork  ;  the  upper  end  of 
the  tube  should  be  drawn  to  a  point.     To  do  this,  heat 
the  tube  an  inch  from  the  end  in  the  flame  until  soft,  and 
then  pull  it  out  to  a  fine  thread  and  break  it.     The  hole 
in  the  upper  end  of  the  tube  should  not  be  larger  than  a 
small   pinhole.     The    cork,    unless   it  be   a   good    one, 
should  be  well  coated  with  wax.     An  excellent  wax  for 
the  purpose  may  be  made  and  applied  as  follows  :  Hard 
paraffine,  two  parts  ;  soft  paraffine,  one  part ;  melt  to- 
gether, and,  while  hot,  pour  a  few  drops  into  a  vessel  of 
cold  water  ;  remove  these  quickly  while  still  warm,  and 
apply  to  the  cork.     A  coating  of  tallow  on  the  cork  will 
answer  the  purpose. 

2.  The  bent  tube  used  in  making  oxygen  in  previous 
lessons  ;  a  short  piece  of  rubber  tubing  ;  a  clay  pipe. 

3.  A  piece  of  glass  tubing,  about  half  an  inch  in  diame- 
ter and  two  feet  long. 

4.  A  handful  of  scraps  of  zinc. 

5.  Hydrochloric  acid. 

6.  Test-tubes,  or  small  two-dram  bottles. 

Experiments. 

i.  Clip  the  zinc  scraps  into  small  pieces,  and  put 
enough  into  the  wide-mouthed  bottle  to,  at  least,  cover 
the  bottom.  Cover  with  water  and  add  the  acid  until  a 
brisk  bubbling  takes  place.  Allow  this  to  continue  three 
or  four  minutes  till  the  air  in  the  bottle  has  been  driven 
put. 


January]  CHE  MIS  TR  Y.  1 99 

2.  Press  tightly  into  the  bottle  the  cork  with  the  tube 
in  it.     What  evidence  is  there  of  a  change  taking  place 
in  the  bottle.     Wrap  a  towel  or  cloth  around  the  bottle 
as  a  precaution  against  a  possible  explosion.      This  will 
prevent  injury  from  flying  pieces  of  glass. 

3.  Apply  a  lighted  match  to  the  tip  of  the  glass  tube. 
This  is  called  the  philosopher's  candle.     What  evidence 
have  you  of  the  character  of  the  work  being  done  by  the 
acid  and  zinc  ? 

4.  Are  the  bubbles  formed  inside  the  bottle  filled  with 
air  ? 

5.  Feel  the  sides  of  the  bottle  ;  is  the  gas  coming  out 
at  the  top  of  the  tube  steam?     How  can  you  decide  this 
question  ? 

6.  Is  the  gas  oxygen  ?     Is  it  carbon  dioxide  gas  ? 

7.  How  does  the  flame  differ   from  that  of  ordinary 
gas  or  a  lamp  ? 

8.  Hold  a  small  piece  of  iron  wire  in  the  flame  for  a 
short  time,  and  then,  when  cool,  hold   it  for  the  same 
length  of  time    in  the  flame  of  a  candle  ;  what  differ- 
ence in  the  result  ? 

9.  How  does  the  light-giving  power  of  the  flame  differ 
from  that  of  a  candle  ? 

10.  Take  the  large  glass  tube  and  lower  it  gently  over 
the  flame  ;  with  the  flame  at  different  heights  inside  the 
tube,  can  you  detect  any  sound  ? 

11.  While   the   sound    is  being  produced,  watch   the 
flame  closely  ;  what  changes,  if  any,  does  it  undergo? 

12.  Can  you  account  for  the  sound  ?     The  full  consid- 
eration of  this  question  had  probably  better  be  referred 
to  some  future  time  when  the  subject  of  sound  is  being 
studied.     If  possible,  try  tubes  having  different  diameters 
and  of  different  lengths. 


200  NA  TURE  STUD  Y.  [January 

13.  What  forms  in  the  upper  part  of  the  tube  when  it 
is  held  over  the  flame  ?     Can  you  account  for  it  ? 

14.  Extinguish  the  flame  ;  hold  a  test  tube  inverted 
over  the  tube  through  which  the  gas  is  escaping.     After 
two  or  three  minutes,  remove  the  test  tube,  and,  still  keep- 
ing it  inverted,  apply  a  lighted    match   to    its   mouth. 
Compare  the  result  with  a  similar  experiment  performed 
with  oxygen. 

15.  In  the  same  manner  fill  a  test  tube  and  remove  it 
and  turn  the   mouth   upward  ;    after  a  minute  apply  a 
lighted  match  to  the  mouth.     Is  there  any  evidence  of 
gas  in  the  tube  ? 

16.  Fill  the  test  tube  again,  remove,  and  keep  it  invert- 
ed.    Bring  the  mouth  of  the  tube  close  to  the  mouth  of 
a  second  tube,  also   inverted,   and   incline  it   until  the 
mouth  of  the  first  is  turned   upward   under  the  second. 
Apply  a  lighted  match  to  the  mouth  of  the  second  while 
it  is  still   inverted.       These  operations  should  be  per- 
formed as  quickly  as  possible. 

17.  Connect  the  glass  tube  by  means  of  the  short  rub- 
ber tube  with  the  stem  of  a  clay  pipe.     With  some  strong 
soapsuds  blow  some  bubbles.     When  they  break  loose 
from  the  pipe  touch  them  with  a  lighted  taper.     Do  not 
apply  the  flame  to  the  pipe  bowl,  nor  to  the  bubbles 
until  they  are  entirely  free  from  it. 

18.  What  do  the  experiments,  14  to  17  inclusive,  show 
you  as  to  the  character  of  this  gas  ?     The  gas  formed  is 
called  Hydrogen.     Its  symbol  is  H. 

19.  In  what  respects  is  hydrogen  like  air?     How  does 
it  differ  from  air  ? 

20.  Compare   it   with   the  CO3  (read  carbon  dioxide) 
that  was  studied  in  November. 

21.  How   do   the   pouring    processes   by   which    the 


January]  CHEMlSTR  Y.  2O I 

gases   were    transferred    from    one    vessel   to   another 
differ  ? 

22.  Compare  the  effects  of  CO3,  O,  and  H,  and  air, 
upon  the  lighted  match. 

23.  Compare  the  methods  by  which  COa,  O,  and  H  are 
obtained  ;  in  what  respect  is  the  process  the  same  in  all 
the  cases  ? 

24.  Examine  the  contents  of  the  bottle  after  the  bub- 
bling has  ceased  ;  is  the  zinc  changed  ?      What  kind  of 
a  change  has  taken  place  ? 

25.  Try  some  of  the  fluid   which   remains   upon  fresh 
zinc  ;  is  it  like  the  acid  you  started  with  ? 

26.  Will  fresh  acid  continue  to  act  upon  the  solids  left 
in  the  bottle  ? 

BOOK    FOR   REFERENCE.       Humboldt    Library,    No.   99,    Nature 
Studies,  chap.  i. 


Meteorology 

1.  In  which  month  during  the  period  included  in  your 
record    has   the    temperature   been    most    diminished  ? 
Can  you  see  a  reason  for  this  ? 

2.  In  which  month,  in  the  same  period,  has  there  been 
the  least  variation  in  temperature  ? 

3.  Does  the   rate  of  variation  in  temperature  corre- 
spond in  any  way  to  the  variation  in  length  of  the  noon 
shadow  ? 

4.  Judging  from  the  slant  of  the  sun's  rays,  are  we 
receiving  more  or  less  heat  from  the  sun  than  we  re- 
ceived in  December  ?     What  does  the  thermometer  tell 
us? 

5.  What  has  been  the  prevailing  wind  for  the  month  ? 
Compare  with  previous  months. 

6.  Is  the  wind  more  or  less  variable  than  it  was  during 
the  autumn  months  ? 

7.  How  has  the  prevailing  wind  affected  the  tempera- 
ture ? 

8.  What  wind  has  accompanied  the   lowest  tempera- 
ture ?     The  highest  ? 

9.  What  was  the  greatest  range  of  temperature  noted 
in  any  week  ?     What  was  the  range  during  the  month  ? 

10.  How  does  the  number  of  rainy  or  snowy  days  com- 
pare with  that  of  December  ? 

11.  How  does  the  amount  of  rainfall   compare  with 
previous  months  ? 


January]  METEOROLOGY.  203 

12.  From   what  direction   do   the  rains  come?     The 
snows  ? 

13.  Do  you  notice   any   uniform   variation  in  tempera- 
ture before,  during,  and  after  a  storm  ? 

14.  At  what   temperature   has   the   most  snow  fallen  ? 
The  heaviest  rains  ? 

15.  Does  the  size  of  the  snowflakes  vary  with  the  tem- 
perature ? 

16.  Does  the  barometer  in  any  way  indicate  uniformly 
the  approach  of  a  storm  ? 

17.  Do  rain  and  snow  storms  affect  it  in  the  same  way  ? 

18.  When  does  it  show   uniformly  the  greater  height, 
on  warm  or  cold  days  ?     What  has  been  its  greatest  range 
in  each  week  and  during  the  month  ? 

19.  How  do  the  clouds  during  this  month  compare  in 
kind  and  elevation  with  those  of  the  previous  months  ? 

20.  What  differences,  if  any,  do  you  notice  between  a 
rain  cloud  and  a  snow  cloud  ? 

STUDY  OF  THE   WEATHER   BUREAU   MAPS. 

21.  What  quarter  of  the   United   States  has  had  the 
Low  Aiea  most  frequently  during  the  month  ?     The  High 
Area? 

22.  What   region    has   been   visited   by   the   severest 
storms  ?     Compare  with  December  in  this  respect. 

23.  What  has  been  the  most  southern  point  reached 
by  the  zero  isotherm  during  the  month  ?     What  range  of 
latitude  was  crossed  by  this  isotherm  ? 

24.  What  was  the  most  southern  point  reached  by  the 
isotherm  32°  ?    What  range  of  latitude  did  it  cover  ? 

25.  Can   you    determine   the  direction    of   the   great 
storms  during  the  month  ?     In  what   regions  have  they 
originated  ? 


204  NATURE  STUDY.  [January 

26.  What  places  stand  on  the  snow  line  during  this 
month  ?     Compare  with  December. 

27.  Where  does   the  snow  line  bend  farthest  south? 
Farthest  north  ?     What  is  the   range  of  latitude  covered 
by  the  snow  line  ?     Can  you  see  any  reason  for  this  vari- 
ation ? 

28.  What  influence  have   the  Great   Lakes  had  upon 
the  snow  line  ?      The    mountain    systems  ?     The  river 
valleys  ? 

29.  How  does  the  climate  west  of  the  Rocky  Moun- 
tains differ  from  that  on  the  east  ? 

30.  Contrast  the  Atlantic  coast  with  the  Mississippi 
valley. 

BOOK    FOR   REFERENCE.      Humboldt   Library,    No.    99,   Nature 
Studies.     Chapter  on  Snow.  . 


astronomy 

The  problems  in  this  subject  which  offer  themselves 
for  study  in  the  changing  seasons  and  recurring  day  and 
night,  and  through  the  observation  of  the  stars  and  the 
planets,  have  been  of  deep  interest  to  mankind  since  the 
earliest  times.  They  present  every  degree  of  difficulty  ; 
the  simplest  lie  within  the  grasp  of  the  primary  pupil, 
while  the  solution  of  those  most  abstruse  has  engaged  the 
highest  intellectual  power  of  the  human  mind. 

It  is  not  necessary  to  take  up  all  the  problems  that 
may  suggest  themselves  during  any  month  ;  but  enough 
should  be  considered  to  give  a  meaning  to  the  daily 
meteorological  record  that  has  been  kept,  so  that  keep- 
ing it  may  not  sink  to  the  level  of  lifeless  routine  work. 
If  the  records  have  been  faithfully  made,  by  this  season 
abundant  data  will  be  at  hand,  which  will  form  a  good 
basis  for  most  interesting  work. 

1.  How  is  the  length  of  day  and  night  changing  this 
month  ?     Is  the    change   the   same   that   occurred    last 
month  ? 

2.  Compare  the  rate  of  change  during  the  first  week 
with  that  during  the  last  one.     Can  you  account  for  the 
difference  ? 

3.  Compare  the  rate  of  change  during  January  with 
the  corresponding  weeks   in   December.     Can  you  ex- 
plain why  the  rate  is  much  the  same  ? 

4.  Is  the  period  of  daylight  this  month  being  length 
ened  by  additions  at  both  morning  and  evening  ? 

205 


206  NATURE  STUDY.  [January 

5.  At  which  time  is  the  greatest  addition  made  ?     Why 
should  the  additions  not  be  the  same  at  both  ends  of  the 
lighted  period  ? 

6.  Refer  -to  the  record  for  previous  months  ;  is  there 
a    corresponding   difference    while    the  day   is  growing 
shorter?     Make  use  of  a  globe  in  trying  to  find  out  why 
the  lighted  period  is  not  either  increased  or  diminished 
by  equal  times,  morning  and  evening. 

7.  When  is  the  increase  or  decrease  in  day's  length 
nearly  equally  divided  between    morning  and  evening  ? 
When  is  it  most  unequally  so  divided  ? 

8.  Examine  the  noon  marks  made  this  month.     (See 
description  of  apparatus  in  September  work.)     How  do 
the  spaces  between  the   marks  compare  with  those   of 
previous  months  ? 

9.  What  does  the  variation  in  the  length  of  the  space 
indicate  ?     Try  to  illustrate  by  use  of  a  globe. 

10.  Is  the  limit   of  the  shadow  moving  in  the  same 
direction   as  it  did  last  month  ?     What  is  the  meaning 
of  this  ?     Is  it  moving  at  the  same  rate  ?     Show  why, 
using  a  globe,  this  is  so? 

11.  Can  you   tell    from  a  study  of   the   noon    marks 
whether  we  are  receiving  more  or  less  heat  from  the  sun 
than  we  received  last  month  ?     Consult  your  meteoro- 
logical record  and  note  the  variation  in  the  temperature 
this  month. 

12.  What  is  the  smallest  angle  that  the  sun's  rays  at 
noon  have  made  with  the  horizon  ?     Use  the  instrument 
described  in  the  September  work  for  making  the  measure- 
ment. 

13.  Try  to  show  why  this  angle  is  smallest  during  this 
part  of  the  year. 

14.  What  effects  depend  upon  the  size  of  this  angle  as 


January]  ASTRONOMY.  207 

a  cause  ?     Is  the  angle  increasing  or  diminishing  at  pres- 
ent ? 

15.  What  effects  are  noticeable  at  present  that  are  due 
to   its   changing   size  ?      Is    it   affecting    temperature  ? 
Why? 

1 6.  In   which  of  the  previous  months  was  the  angle 
about  the  size  that  it  is  the  last  of  January  ?     How  does 
that  month  compare  with   January  as  to    temperature, 
length  of  day  and  night,  etc.  ?     Try  to  explain  why  they 
are  alike  in  §pme  respects  and  different  in  others. 

17.  How  are  the  points  at  which  the  sun  rises  and  sets 
moving  on  the  horizon  at  present?     Can  you  show  why 
this  is  so,  using  a  globe  ? 

1 8.  What  is  the  greatest  variation  in  the  time  of  the 
rising  or  setting  of  the  moon  on  two  successive  days  ? 

19.  Can  you   think  of  the  conditions  necessary  that 
would  cause  it  to  rise  at  the  same  time  every  evening  ? 

20.  Under  what  conditions  would  the  moon  rise  in  the 
west  and  set  in  the  east  ?     Would  its  appearance  change 
during  the  night  ?     (This  is  true  of  one  of  the  moons  of 
the  planet  Mars.) 

21.  The  planet  Venus  (see  Astronomy  for  September) 
moves  around  the  sun  in  two  hundred  and  twenty-five 
days.     Can  you  explain  why  this  planet  has   changed 
from  an   evening  to  a  morning  star  ?     Try  to  see  the 
planet  moving  in  its  orbit  and  in  its  proper  relation  to 
the  earth  and  sun.     Use  symbols  sparingly  and  only  to 
illustrate,  not  to  take  the  place  of  the  real  objects. 

22.  How  long  does  it  shine  as  morning  star  and  as 
evening  star  respectively  ? 

23.  Suppose  the  earth  and  Venus  are  on  the  same  side 
of  the  sun  and  in  a  line  with  it,  what  will  be  the  position 
of  the  three  bodies  at  the  end  of  one  year  ? 


208  NATURE  STUDY.  [January 

24.  Can  Venus  ever  appear  to  us  except  as  a  morning 
or  an  evening  star  ? 

25.  Will  she  exhibit  phases  corresponding  to  those  of 
our  moon  ? 

26.  In  what  position  will  we  see  the  largest  part  of  the 
disk  ?     In  what  position   will  we  see  the  smallest  part 
of  it? 

27.  Constellations  the  same  as  last  month  ;  how  have 
they  changed  their  positions  ? 

BOOKS  FOR  REFERENCE.  Humboldt  Library  :  No.  14,  Wonders 
of  the  Heavens.  No.  20,  The  Romance  of  Astronomy.  No.  I, 
Light  Science  for  Leisure  Hours,  Chapter  on  Venus. 


SOUTH  AMERICA.     PRODUCTIONS. 

The  pupils  should  model  a  relief  map,  and  with  this 
before  them  endeavor  to  work  out  the  reason  for  the 
character  of  the  various  productions,  as  far  as  they 
are  results  of  the  climatic  conditions  of  latitude,  eleva- 
tion, winds,  rainfall,  coast  line,  and  ocean  currents. 

1.  Judging  from  the  range  of  latitude  covered  by  the 
continent,  what  contrasts  'must  be  expected    in   animal 
and  vegetable  productions? 

2.  Compare  South  America  with  North  America  in 
this  respect.     What  different  conditions  will  tend  to  pro- 
duce contrasts  in  the  two  continents  in  corresponding 
latitudes  ? 

3.  What  contrasts  in  productions  would  you  expect  to 
find  in  South  America  in  the  equatorial  regions  ? 

4.  Is  it  possible  that  the  productions  belonging  usually 
to   the    temperate   regions   may    be   found    within   the 
tropics? 

5.  What  contrasts  would  you   expect  to  find  on  the 
opposite    sides    of   the    Andes    Mountains    within   the 
tropics  ? 

6.  How  must  the  productions  of  the  Atlantic  and  the 
Pacific  coast  lines  differ  within  the  tropics? 

7.  Would  you  expect  much  contrast  between  the  At- 
lantic coast  line  and  the  interior  in  the  equatorial  region  ? 

8.  Would  you  expect  a  similarity  or  contrast  between 

209 


210  NATURE    STUDY,  [January 

the  Pacific  coast  of  South  America  and  that  of   North 
America  ? 

9.  What  are  the  most  active  influences  which  deter- 
mine the  productions  on  these  coasts  in  the  two  conti- 
nents ? 

10.  What  must  be  the  character  of  the  Pacific  coast 
productions  of  South  America  in  the  temperate  zone? 

i  r.  Do  you  see  any  reason  for  their  being  different  on 
the  eastern  side  of  the  mountains  ? 

12.  Contrast  this  region  with  the  corresponding  lati- 
tude of  North  America. 

13.  Where   are   the    fertile    river    valleys    in    South 
America  ? 

14.  Locate  on  molded  map  the  great  forest  area  of  the 
continent.      What  are  the  conditions  favorable   for  it  ? 
What  valuable  woods  are  obtained  from  this  great  forest 
region  ?     Read    a    description    of    the    Amazon    river 
basin. 

15.  How  do  the    climatic  conditions   favor  the  great 
grass  plains  of  the  Orinoco  basin,  the  Llanos  ?     Are  the 
same  conditions  favorable  to  forests? 

1 6.  Where    else   are    there    grass    regions    in    South 
America  ? 

17.  To  what  regions  of  North  America  do  they  corre- 
spond ? 

1 8.  Locate  on 'the  map  the  region  from  which  spices, 
gums,  and  medicinal  plants  are  obtained. 

19.  Locate    in     the    same    way    the    coffee-growing 
region. 

20.  What  do  the  exports  from  Buenos  Ayres  tell  as  to 
the  productions  of  the  surrounding  country  ?     Compare 
with  the  exports  of  Rio  Janeiro. 

21.  Locate  the   regions  of   greatest    mineral   wealth, 


January]  GEOGRA PHY.  2 1 1 

What  minerals  are  found  in  the  Andes  Mountains?     In 
the  Brazilian  highland  ? 

22.  What  are  the  chief  cities  of  the  mining  regions? 
Read  the  Story  of  the  Incas  and  the  history  of  the  con- 
quest of  Peru. 

BOOKS  FOR  REFERENCE.  Guyot's  Physical  Geography.  Humboldt 
Library,  Nos.  n  and  12.  The  Naturalist  on  the  River  Amazon. 


The  observations  of  the  effects  of  frost  and  freezing  as 
agencies  that  are  at  work  during  the  winter  season  in 
changing  the  face  of  nature  should  be  continued  this 
month  along  the  lines  commenced  in  December.  The 
experiment  suggested  under  Physics  for  November, 
showing  the  expansive  force  of  freezing  water,  may  with 
profit  be  recalled  or  repeated  and  applied  in  this  con- 
nection. Examination  should  be  made  of  the  soil  in  dif- 
ferent places  to  determine  the  depth  ^  which  the  ground 
is  frozen  under  various  conditions.  It  will  be  a  matter  of 
interest  and  profit  at  this  time,  while  outdoor  work  is 
impracticable,  on  account  of  the  inclemency  of  the  season, 
to  consider  the  nature  of  fossils,  and  to  try  to  read  some  of 
the  earth's  history  recorded  by  them.  The  early  ideas 
as  to  the  origin  and  meaning  of  fossils  were  as  monstrous 
as  they  now  seem  curious  and  amusing.  Of  all  the  ob- 
served acts  in  nature  which  man  has,  from  time  to  time, 
endeavored  to  reconcile  to  his  preconceived  notions  of 
the  origin  and  history  of  this  world,  nothing  has  proved 
more  refractory  than  these  foot-prints  of  a  long  bygone 
age.  Although  it  required  some  hundreds  of  years  for 
early  scientists  to  get  the  first  glimpse  of  the  truth  con- 
cerning fossils,  yet  so  obvious  are  the  general  facts  of 
their  history,  it  was  only  necessary  for  the  mind  to  ap- 
proach the  subject  unbiased  by  preconceived  notions 
and  beliefs  to  have  their  true  character  recognized.  The 
course  of  early  inquiries  into  the  nature  of  fossils  affords 


January]  GEOLOG  Y.  213 

one  of  the  strongest  illustrations  given  on  the  page  of 
history  of  how  one's  prejudice  or  belief  may  become  an 
insurmountable  barrier  between  him  and  the  simple  truth. 
Even  children  of  primary  grades  will,  without  prompting, 
reason  correctly  about  the  origin  of  fossils,  though  of 
course  they  lack  almost  totally  the  idea  of  the  time  in- 
volved. 

The  fossil  in  itself  is  a  matter  of  comparatively  little 
interest,  but  when  it  is  used  as  a  key  to  unlock  the  se- 
crets of  the  past;  when  through  it  the  child  calls  up  a 
great  picture  of  the  world  and  nature  as  they  mm  t  have 
been  when  it  was  a  living  thing  ;  when,  with  it  in  hand, 
he  sees  the  succeeding  ages  roll  by,  each  with  a  charac- 
ter of  its  own,  then  it  becomes  one  of  the  most  powerful 
means  at  the  teacher's  command  for  broadening  and 
strengthening  his  pupil's  conception  of  the  universe. 
The  teacher  must  carefully  avoid  the  mistake  of  being  in 
too  much  haste.  The  idea  to  be  attained  is  vast,  and  is 
destined  to  forever  grow.  Let  the  pupil  have  ample 
time  to  fill  in  his  picture  of  those  distant  ages  with  land, 
water,  sunlight,  darkness,  plants,  animals,  air,  blue  sky, 
lowering  clouds,  lightning,  thunder,  rain,  snow,  ice,  and 
everything  that  the  existence  of  that  one  living  thing, 
which  we  now  know  as  a  fossil,  implied.  Without  due 
deliberation  and  thought,  something  will  be  omitted  which 
will  mar  the  symmetry  of  the  creation  and  spoil  the 
beauty  of  the  scene. 

For  an  excellent  resume  of  the  early  theories  regard- 
ing fossils,  the  teacher  is  referred  to  Lyell's  Principles  of 
Geology,  vol.  i,  page  33,  et  seq. 

1.  Examine  the  ground  in  the  locations  observed  last 
month  ;  has  it  been  frozen  to  greater  depth  ? 

2.  If  opportunity  offers,  notice  a  trench  dug  through 


2I4  NATURE   STUDY.  [January 

the  street ;  is  the  ground  frozen  deeper  under  the  cobble 
stones  than  it  is  under  the  sod  ?  Can  you  account  for 
the  difference  ? 

3.  Can  you  find  any  stones  that  are  being  crumbled  by 
frost  ? 

4.  Where  is  the  ground  frozen  to  a  greater  depth,  un- 
der the  trees  or  in  an  open  space  ?     Where  there  is  sod 
or  where  the  ground  is  bare  ? 

5.  Can  you  notice  any  differences  in  freezing  that  you 
know  are  due  to  differences  in  soils  ? 

6.  Among  the   fossil   plants   that  are  perhaps    most 
easily  obtained  by  pupils  are  some  of  those,  ferns  it  may 
be,  of  the  Carboniferous  or  Coal  Period.     The  following 
questions  and  suggestions  refer  specially  to  such  a  fossil, 
though  they  may  readily  be  adapted  to  any  fossil  plant. 
These,  or  at  least  the  impressions  of  them,  are  frequently 
found  in  the  lumps  of  coal  in  the  bin,  and  pupils  should 
watch  for  them. 

7.  Is  there  any  doubt  as  to  what   has  left  its  imprint 
upon  the  stone  or  coal  ?     What  are  the  marks  that  make 
you  certain  of  the  correctness  of  your  answer  ? 

8.  Does  it  in  any  respect  resemble  any  plants  of  the 
present   time  ?     Can   you    tell    what  part    of   the  plant 
it  is? 

9.  Is  the  fossil  under  examination   the  original  plant, 
or  a  cast  of  it  ?     By  cast  this  is  meant  :  that  the  space 
that  was  once  occupied  by  the  plant  has  been  filled  with 
a  stony  substance  that  bears  the  shape  and  marks  of  the 
once  living  thing.     If  neither  a  cast  nor  the  original  sub- 
stance, can  you  make  out  whether  it  is  more  than  merely 
the  imprint  of  some  plant  ? 

10.  Can  you  discover  any  evidence  that  the  leaves  were 
veined  like  those  of  the  present  day  ? 


January]  GEOLOGY.  215 

n.  Can  you  form  any  idea  as  to  the  size  the  plant 
must  have  been  ? 

12.  From  what  you  know  of  ferns  which  you  have  seen, 
within  what  range  of  heat  and  cold  is  it  likely  that  this 
plant  lived  ? 

13.  Was  the  cold  as  severe  as  that  of  Greenland  at 
present  ?     Is  it  possible  that  snow  may  have  fallen  where 
it  grew  ?     Did  it  rain  there  ?     Do  you  suppose  the  sun 
shone  upon  it  ?     How  much   warmer  may  the  sun  have 
shone  upon  it  than  it  shines  upon  us  in  summer? 

14.  Do  you  know  where  it  was  found  ?     Do  ferns  now 
grow  in  that  region  ?     How  may  that  region  have  differed 
from  its  present  condition  when  the  fossil  grew  there  ? 

15.  Is  it  likely  that  it  grew  on  a  high  mountain  ?     Did 
it    grow    in    a   desert  ?     Could    it    have    grown    in    a 
marsh  ? 

16.  Is  there  evidence  as  to  whether  it  grew  in  a  forest 
or  in  open  fields  ?    What  would  you  suppose  concerning 
the  fertility  of  the  soil  that  produced  it  ?     . 

17.  Can  you  tell  whether  or  not  it  belonged  to  a  plant 
that  shed  its  leaves  ?     Was  this  fossil  decayed  before  it 
fell  to  the  ground  ? 

1 8.  Do  you  think  this  fossil  plant  bore  as  many  leaves 
as  our  plants  do  at  present  ?     Were  plants  growing  as 
thickly  on  the  ground  as  they  do  now  ? 

19.  How   does  it    happen  that    fossil   leaves  are   not 
more  abundant?     Are  the  leaves  that  you  noticed  fall 
last  autumn  likely  to  become  fossilized  ? 

20.  Did  this  fossil  leaf  decay  after  falling  to  the  ground 
as  soon  as  most  leaves  do  that  you  have  noticed  ? 

21.  What  must  have  happened  soon  after  it  fell,  which 
started  it  on  the  way  to  become  a  fossil  ? 

22.  Which  is  the  more  likely,  that  it  fell  in  a  wet  place 


216  NATURE   STUDY.  [January 

or  in  a  dry  one?     In  which  place  would  it  probably  be 
more  quickly  covered  ? 

23.  In  which  kind  of  covering,  wet  or  dry,  would  the 
more  perfect  imprint  be  made  ?     In   which  kind   would 
the  leaf  be  the  longest  preserved  ?     In  which  would  the 
imprint  be  the  better  preserved  before  the  rock  hard- 
ened ? 

24.  Was  it  covered  with  fine  or  coarse  material  ? 

25.  If  you  think  it  was  buried  in  a  dry  place,  what 
agency,  probably,  did  the  work  ?     Can  you   by  digging 
down  into  the  soil  find  leaves  that  are  as  perfect  as  this 
one? 

26.  On  the  supposition   that  it  fell  into  a  swamp,  or 
into  water,  by  what  means  do  you   think   it  could  have 
been  buried  ? 

27.  If  you  think  it  fell  into  water,  can  you  find  any 
evidence   as   to    whether   it    was    running   or   standing 
water  ? 

28.  If  the  fossil  you  have  is  a  cast  of  the  plant  form, 
how   was   that   cast   made  ?     Would   it  be   more  easily 
formed  in  dry  or  in  wet  ground  ? 

29.  In  case  you  have  but  the  imprint,  can  you  tell  what 
has  become  of  the  plant  ?     Why  was  the  imprint  not 
destroyed  ? 

30.  If  your  fossil  came  from  a  coal  mine,  or  near  it,  do 
you  know  what  thickness  of  earth  there  was  above  it  ? 
How  deep  are  some  of  the  coal  mines  that  you  have  seen 
or  read  about? 

31.  Are  there    layers   of   solid    rock  above   the   coal 
seams  ? 

32.  In  what  way,  most  likely,  was  this  great  covering- 
deposited  ? 

33.  If  this  mass  of  earth  and  rock  was  deposited  by 


January]  GEOLOGY.  217 

water,  what  change  must  have  come  over  the  region  where 
the  fern  grew  ?  What  can  you  infer  about  the  depth  of 
the  water  ? 

34.  Can  you  find  any  evidence  that  will  show  whether 
the  change  was  gradual  or  sudden  ? 

35.  What  is  the  most  reasonable  supposition  that  you 
can  make  which  will  account  for  the  region  where  the 
fossil  grew  becoming  covered  with  water. 

36.  What  other  change  in  the  region   must  have  oc- 
curred after  the  mass  of  earth  was  deposited? 

37.  What  supposition  can  you  make  which  will  explain 
how  the  water  was  removed  ? 

38.  Is  there  any  evidence  of  more  than  one  sinking, 
and  one  elevation  of  the  land  ? 

39.  After  the  water  finally  disappeared,  by  what  means 
do  you  think  the  fossil  became  exposed,  if  it  was  found 
on  or  near  the  surface  ?     What  agencies  that  you  know 
of  are  now  at  work  that  would  tend  to  gnaw  away  its 
covering  ? 

40.  In  looking  back  over  the  possible  history  of  the 
fossil,  can  you  form  any  estimate  of  the  length  of  time 
included  in  it  ? 

41.  In  any  region  that  you  maybe  familiar  with  during 
the  past  few  years,  has  there  been  any  perceptible  depth 
of  material  deposited  ?     What  has  placed  it  there  ? 

42.  Has  there  been  any  perceptible  deposition  in  any 
lake,  large  or  small,  that  you  have  had  opportunity  to 
observe  ? 

43.  Is  there  any  way  of  telling  how  long  it  took  the 
water  to  gather  to  this  region  or  recede  from  it  ? 

44.  It  has  been  estimated  that  the  Mississippi  River 
carries  down    enough   sediment  each    year  to  cover  a 
square  mile  two  hundred  and  sixty-eight  feet  deep.     At 


218  NATURE   STUDY.  [January 

that  rate,  how  long  would  it  take  that  river  to  remove  a 
layer  one  foot  thick  from  its  basin  ? 

45.  At  the  same  rate,  how  long  would  it  take  to  expose 
the  fossil  after  the  water  had  receded,  supposing  it  to 
have  been  buried  five  hundred  feet  deep  ?  If  each  of  the 
other  periods  in  the  history  of  the  fossil  were  as  long, 
what  would  be  its  age  ? 

BOOKS  FOR  REFERENCE.  Humboldt  Library:  No.  6,  Town 
Geology.  No.  38,  Geological  Sketches,  chap.  vii. 


If  the  pupils  have  been  industrious  in  collecting  speci- 
mens of  the  various  kinds  of  rocks  and  minerals  of  the 
neighborhood,  it  will  be  interesting  to  examine  them  with 
a  view  to  learning  something  of  their  chemical  proper- 
ties. A  few  cents'  worth  of  hydrochloric  and  sulphuric 
acids  in  separate  bottles  will  be  all  that  is  necessary.  If 
these  cannot  be  obtained,  use  strong  vinegar. 

1.  Powder  a  small  amount  of  limestone  and  put  it  into 
a  small  bottle  or  test  tube,  add  a  little  hydrochloric  acid, 
and  note  the  result.    Gently  warm  the  test  tube  over  the 
lamp;  what  difference  is  noted? 

2.  In  the  same  way  try  the  limestone  with  dilute  sul- 
phuric acid  ;   compare  with  the  changes  that  occurred 
with  hydrochloric  acid.     Dilute  the  sulphuric  acid  with 
five  or  six  times  its  bulk  of  water,  and  allow  it  to  cool 
before  using ;  add  the  acid  to  the  water,  allowing  it  to 
run  slowly  down  the  sides  of  the  tube. 

3.  In  a  similar  manner  treat  a  piece  of  marble  and 
compare  with  the  limestone. 

4.  Take  some  small  pieces  of  shells,  those  of  oyster  or 
clam,  and  treat  with  acid  ;  how  are  they  like  the  stones? 
If  it  can  be  obtained,  try  in  the  same  way  a  piece  of  chalk 
— not  crayon.     What  is  the  result  ? 

5.  The  bubbling  noticed  when  the  stones  were  placed 
in  acid  is  called  effervescence.    Stones  which  dissolve  in 
acids  with  effervescence,  a  gas  being  formed,  are  said  to 


220  NATURE   STUDY.  [January 

be  calcareous.     They  are  composed  of  the  elements  cal- 
cium, carbon,  and  oxygen. 

6.  Treat  a  small  piece  of  gypsum  with  acid,  compare 
it  with  the  action  of  the  acid  on  marble  and  limestone. 

7.  Break  off  a  small  piece  of  quartz  from  one  of  the 
pebbles  found  on  the  lake  shore  or  the  banks  of  a  stream, 
and  drop  it  into  the  acid  ;  is  there  a  change? 

8.  In  the  same  way  try  a  piece  of  flint  or  any  other 
flinty  hard  stone  in  your  collection  ;  does  the  acid  affect 
them  ?     Test  also  a  piece  of  slate. 

9.  Treat  a  small  piece  of  clay  with  acid  ;    does  it  dis- 
solve ? 

10.  In  the  same  way  try  a  piece  of  sandstone  ;  does  it 
differ  in  any  particular  from  any  of  the  above  ? 

11.  These   hard    stones,  insoluble  in   acid,  are   called 
silicious  stones.     They  are  composed   of  the  elements 
oxygen  and  silicon.     The  clay  is  silicious,  but  contains 
some  impurities. 

BOOK  FOR  REFERENCE.     Humboldt  Library  :  No  6,  Town  Ge- 
ology. 


Zoology 


GENERAL  OBSERVATIONS. 

1.  Keep  a  sharp  lookout  during  the  month  for  return- 
ing birds.     It  is  too  early  to  expect  the  return  of  any 
great  numbers,  yet  some  may  occasionally  be  seen. 

2.  Have  the  winter  visitors  returned  northward  yet  ? 

3.  Are  there  any  signs  of  returning  spring  through  the 
awakening  of  animal  life  ? 

PREHENSION  OF  FOOD. 

The  various  ways  in  which  different  animals  seize  their 
food  and  convey  it  to  their  mouths  form  interesting  sub- 
jects for  study.  The  wonderful  precision  of  the  human 
arm  and  hand  in  these  movements  is  worthy  of  more 
than  passing  attention.  When  baby  begins  to  help  itself 
at  the  table,  the  movements  are  neither  graceful  nor  ac- 
curate. In  attempting  to  seize  the  morsel,  the  unruly 
shoulder-muscles,  which  at  an  early  age  are  the  ones 
chiefly  used  in  guiding  the  hand,  bring  the  hand  down 
wide  of  the  mark.  After  repeated  efforts,  almost  by  ac- 
cident the  hand  comes  within  grasping  distance,  and  the 
fingers,  without  the  slightest  effort  at  individual  arrange- 
ment, close  like  the  claws  of  a  bird.  The  return  move- 
ment is  equally  awkward  ;  the  shoulder-joint  is  stubborn, 
the  elbow  refuses  to  bend,  the  wrist  fails  in  its  duty,  and 
the  chubby  fist  is  sent  on  an  excursion  from  ear  to  ear 


222  NATURE  STUDY.  [February 

before  the  morsel  is  finally  lodged  within  the  anxiously 
waiting  mouth.  But,  see  the  result  of  persistent  training. 
After  a  little  time  the  shoulder  makes  just  the  right 
swing,  the  elbow  makes  exactly  the  right  angle,  the  wrist 
gives  the  hand  the  proper  droop,  and  by  an  accurate  and 
definite  turn  of  the  hand  and  arm  the  fingers  are  mar- 
shalled into  their  appointed  positions  and  the  food  is 
carried  to  the  mouth  with  grace  and  ease.  Absolute 
freedom  and  precision  of  movement  are  acquired,  and 
the  difficulties  are  mastered  so  early  that,  from  our  own 
experience,  we  could  not  even  know  that  they  ever  ex- 
isted. If  teachers  and  parents  were  to  give  as  much 
care  to  muscular  training  for  other  movements,  such  as 
writing,  walking,  lifting,  etc.,  as  they  do  to  those  con- 
cerned in  getting  food  to  the  mouth,  it  is  hardly  too 
much  to  say,  that,  in  the  child's  life,  years  of  time  and 
tons  of  effort  would  be  saved. 

1.  What  animals,  besides  man,  make  use  of  their  fore 
limbs  in  managing  their  food  ?     What  animals,  that  you 
know  of,  make  no  such  use  of  these  limbs  ? 

2.  Is  there  an  essential  difference  in  the  character  of 
the  food  of  these  two  classes  of  animals  ? 

3.  What  movements  of  the  squirrel's  foreleg  are  like 
the  arm  and  hand  ?     In  what  respect  are  the  paws  unlike 
the  hand? 

4.  What  is  the  foot-like  character  retained  by  the  fore- 
paws  ?     Why  is  this  ? 

5.  If  possible  to  do  so,  examine  the  hand  of  a  mon- 
key ;  in  what  respect  is  it  more  hand-like  than  the  fore- 
paw  of  a  squirrel  ? 

6.  What  differences  between  the  cat  and  the  dog  in  the 
use  of  their  forepaws  in  food  getting  ? 

7.  Are  the  cat's  forepaws  more  or  less  hand-like  than 


February]  ZOOLOGY.  223 

those  of   the  squirrel  ?     In  what   respects  ?     The  limbs 
used  in  grasping  are  said  to  be  prehensile. 

8.  How  do  animals  without  prehensile  limbs  seize  their 
food? 

9.  Does  there  seem  to  be  any  correspondence  between 
the  shape  of  the  head  and  the  mode  of  food  prehension  ? 
Notice  the  contour  of  the  heads  of  the  different  animals 
that  make  no  use  of  their  fore  limbs  in  the  prehension  of 
food  ;  compare  them  with  the  heads  of  those  that  use 
their  limbs  for  prehension. 

10.  Does  the  attitude  of  the  body  vary  with  the  pre- 
hensile character  of  the  limbs  ? 

11.  What  parts  of  the  face  are  concerned  in  the  pre- 
hension of  food  ?     What  parts  are  most  used  in  taking 
liquids  ?     In  taking  solids'? 

12.  Study  and  explain  the  process  by  which  we  take  a 
drink  ?     (See  Physics  for  January.) 

13.  What  organs  are  concerned  in  this  operation  ? 

14.  Do  the  dog  and  the  cat  drink  in  exactly  the  same 
way? 

15.  How  do  birds  drink  ?     Why  do  they  throw  their 
heads  backward  ? 

16.  How  do  the  horse,  the  cow,  and  the  sheep  seize 
their  food  ? 

17.  WThy  is  the  tongue  of  a  cat  rough?     Is  the  dog's 
tongue  similar?     Can  you  see  a  reason  for  what  you  ob- 
serve ?     Keep  in  mind  the  wild  state  of  these  animals. 

1 8.  A  cow's  food  differs  very  much  from  that  of  a  cat ; 
yet  her  tongue  is  rough  and  rasp-like  ;  what  reason  can 
you  see  for  this  similarity  in  the  two  animals  ? 

19.  Can  you  account  for  any  differences  observed  be- 
tween the  cow's  tongue  and  that  of  a  horse? 

20.  What  use  does  the  snake  make  of  its  tongue  ? 


224  NATURE  STUDY.  [February 

21.  In  what  way  do  we  use  our  lips  in  taking  food  ? 

22.  What  animals  have  you  observed  that  make  greater 
use  of  their  lips  for  this  purpose  ? 

23.  Can  you  trace  any  correspondence  between  the 
character  of  the  food  and  the  kinds  of  lips  of  different 
animals  ? 

24.  Are  the  teeth  employed  in  the  prehension  of  food  ? 
Compare  different  animals  in  this  respect,  such  as  the 
horse,  the   cow,  the   sheep,  the   squirrel,  the    rabbit,  the 
snake,  the  dog,  and  the  cat,  with  yourself. 

25.  Notice  the  movements  and  the  work  done  by  the 
different  parts  of  the  mouth  in  chewing  or  masticating 
food. 

26.  What  appears  to  be  the  function  of  the  tongue? 
Of  what  tissue  is  it  composecf?     In  how  man}''  ways  can 
you  change  its  form  ?     How  many  different  movements 
does  it  have  ? 

27.  With  the    finger-tip  examine   the  surface   of  the 
teeth.     How  many  teeth  have  you  ? 

28.  How  many  different  kinds  of  teeth  can  you  find 
in  your  mouth  ? 

29.  Compare  your  teeth  as  far  as  possible  with  the 
animals  mentioned  in  (24).     What  variations  ? 

MASTICATION   OF   FOOD. 

1.  Notice  the  movements  made  by  the  jaws  of  different 
animals  in  masticating  their  food.     What  are  the  move- 
ments of  your  own  jaw  ?     Is  the  movement  always  in  the 
same  direction  ? 

2.  Is  the    movement   dependent   upon    the    kind    of 
food? 

3.  Do  the  teeth  correspond  in  either  arrangement  or 
form  with  the  movement  of  the  jaws  ? 


February]  ZOOLOGY.  225 

4.  What  organs  keep  the  food  between  the  teeth  dur- 
ing the  process  of  mastication  ? 

5.  What  appears  to  be  the  particular  function  of  the 
tongue?     How  many  movements  has  it? 

6.  What  part  do  the  front  teeth  play  in  mastication  ? 
How  are  they  adapted  to  their  work  ?     How  many  are 
there  that  are  alike?     They  are  called  incisors. 

7.  What  appears  to  be  the  use  of  the  teeth  next  to  the 
incisors  on  either  side  ?     In  what  animals  are  they  promi- 
nent ?     Do  you  make  any  such  use  of  yours  ?     These  are 
canine  teeth. 

8.  What  use  is  made  of  the  teeth  behind  the  canine 
teeth  ?     How  are  they  adapted  to  their  work  ? 

9.  In  comparing  yourself  with  other  animals  that  differ 
from  you  in  their  food  and  mode  of  mastication,  do  you 
find  corresponding  differences  in  the  teeth  ? 

10.  The  two  teeth  immediately  behind  the  canine  teeth 
are   called   bicuspids,  and   the    remaining   ones   are   the 
molars.     How  many  teeth    have  you  in  all  ?     The  last 
molar,  or  wisdom  tooth,  is  not  cut  until  much  later  than 
the   re*t,  usually   between   the    ages   of  seventeen   and 
twenty-five  years. 

11.  The  parts  of  a  tooth  are  the  crown,  which  is  that 
portion  exposed  above  the  gums  ;  the  root  or  fang,  which 
is  embedded  in  the  jaw  ;  and  the  neck,  that  part  beneath 
the  gum,  but  not  in  the  bony  socket. 

12.  What  teeth  are  most  prominent  in  the  dog  and  in 
the  cat  ?     In  the  squirrel  ?     Why  the  difference  ? 

13.  What  is  the  movement  of  the  jaws  when  the  in- 
cisors are  employed  ?     The  molars  ? 

14.  Do   the    cat    and    the    dog    have    the    grinding 
motion    when    using   their  back  teeth  ?     What   adapta- 
tion do  you  see  between  the  movements  of  their  jaws, 


226  NATURE  STUDY.  [February 

the   character   of    their   teeth,  and    the   kind    of    food 
they  eat  ? 

15.  Some  of  the  lower  animals  show  a  curious  and 
automatic  regularity  in  the  movements  of  the  jaw  in  masti- 
cation.    The  cow  in  chewing  her  cud  will  move  her  jaw 
with  great  regularity  from  twenty-eight  to  thirty  times 
before  swallowing  the  mass  thus  ground  up. 

16.  What  reasons  can  you  see  for  brushing  the  teeth  ? 
Should    a   toothpick   be    used  ?      Never   use   a   pin    or 
metallic  toothpick  of  any  kind,  as  it  is  likely  to  injure  the 
thin  but  very  hard  and  brittle  layer  of  enamel  which 
covers  the  outside   of   the  tooth.     Children  should  be 
taught  to  cleanse  their  teeth  regularly  after  meals  as  soon 
as  they  are  able  to  manage  a  brush.     People  usually  be- 
gin  to  pay  serious  attention   to  their  teeth  only  after 
irreparable  mischief  has  been  wrought  by  neglect. 

INSALIVATION   AND  SWALLOWING. 

1.  What   further   preparation    for   swallowing,  beside 
being  masticated,  does  the  food  undergo  ?     Whera  does 
the  moisture  in  the  mouth  come  from  ? 

2.  By  closing  the  teeth  and  drawing  the  tip  of  the 
tongue  backward   and    forward,    the  fluid  called  saliva 
may  be  noticed  collecting  under  the  end  of  the  tongue. 
This  arises  from  two  organs  called  salivary  glands  which 
lie  under  the  tongue,  and  whose  office  it  is  to  provide 
part  of  the  fluid  necessary  to  soften  and  partially  dis- 
solve and  digest  a  portion  of  the  food  while  it  remains  in 
the  mouth.     The  fluid  is  conveyed  from  the  glands  by 
two  tubes  called  ducts,  one  of  which  opens  in  each  half 
of  the  under  part  of  the  tongue.     These  openings  may  be 
seen  by  looking  into  one's  mouth,  by  means  of  a  good 


February]  ZOOLOGY.  227 

light  and  a  mirror,  by  turning  the  tip  of  the  tongue  up- 
ward. They  appear  about  the  size  of  pin-holes.  Near 
these  two,  other  ducts  open  which  come  from  similar 
glands  located  farther  back  under  the  tongue.  By 
drawing  the  cheeks  in  between  the  teeth  with  a  kind  of  a 
sucking  motion,  note  the  moisture  which  seems  to  come 
from  the  cheeks.  Opposite  the  second  molar  teeth  a 
duct  opens  in  each  cheek  which  leads  from  a  gland 
located  about  midway  betweed  the  ear  and  the  angle  of 
the  lower  jaw.  These  are  called  the  parotid  glands  ; 
those  farthest  back  under  the  tongue  are  the  sub- 
maxillary,  and  those  in  front,  the  sublingual  glands. 

3.  How  does  the  saliva  differ  from  pure  water  ?     What 
use  has  it  besides  that  of  softening  and  dissolving  the 
food  ? 

4.  When  the  food  has  been  fully  prepared  for  swallow- 
ing, to  what  point  is  it  gathered  ?     It  is  then  called  a 
bolus. 

5.  How  is  the  bolus  forced  back  out  of  the  mouth  ? 
Note  the  position  of  the  jaws  during  this  act. 

6.  What  part  of  the  swallowing  is  beyond  the  control 
of  the  will  ? 

7.  What  prevents  the  food  from  being  crowded   up- 
ward into  the  nasal  passages  behind  the  mouth  ?     Notice 
the  muscular  curtain  with  the  elongated  uvula  hanging 
down  in  the  back  part  of  the  mouth.     How  does  it  help 
in  swallowing  ? 

8.  On  the  side  of  the  mouth  in  this  region  look  for 
almond-shaped  bodies  called  the  tonsils.     They  secrete  a 
slippery  substance   called    mucus.     Note   also   the   red 
pillars  of  the  fauces  on  the  sides  of  the  mouth  at  the 
entrance  to  the  throat ;  these  close  in  above  the  food  and 
keep  it  going  downward. 


Botany 

This  is  the  last  of  the  winter  months,  according  to  the 
calendar,  at  least,  and  it  should  not  be  allowed  to  pass 
without  giving  the  pupils  opportunity  to  become  familiar 
with  the  winter  condition  of  plants.  Twigs  from  differ- 
ent kinds  of  trees  and  of  the  same  tree  in  different  locali- 
ties should  be  examined,  with  a  view  to  ascertaining  what 
per  cent,  of  buds  is  killed.  It  should  also  be  noticed 
whether  the  twigs  themselves  all  survive  alike.  Unfor- 
tunately, in  this  latitude,  a  few  mild  days  sometimes  come 
in  this  month  which  coax  the  buds  into  unseasonable 
activity.  These  are  then  caught  by  later  frosts,  and  the 
plant  must  fall  back  upon  its  reserve  store.  It  should 
be  noticed  which  trees  and  plants  are  thus  most  sensi- 
tive to  the  spring-like  weather,  and  what  ones  are  least, 
or  not  all  affected  by  it. 

1.  Can  you  find    out   whether   the   buds   are   frozen 
through  and  through  during  the  winter? 

2.  What  is  the  location  of  those  buds  that  have  been 
killed,  on  the  ends  of  the  branches  or  near  the  trunk  ?     A 
bud  that  has  been  killed  may  be  easily  recognized  by  its 
being  brown  or  black  in  the  center,  while  living  buds  are 
green. 

3.  Have  you  been  able   to  find   any  twigs  that  are 
killed  ? 

4.  Can  -you  tell  whether  the  roots  have  been  frozen  or 
not  ? 

5.  Are  the  grass-blades  killed  in  the  winter?     Are  the 

228 


February]  BOTANY.  229 

roots  killed  ?     Dig  up  some  of  the  roots  and  find  out  the 
kind  which  some  of  the  different  grasses  have. 

6.  Can  you  find  any  mosses  that  seem  to  be  alive  at 
this  season  ? 

7.  Look  on  the  different  sides  of  the  trunks  of  trees 
for  the  green  moss-like  covering  that  sometimes  may 
be  seen  there. 

8.  Examine  some  pine  trees  of  different  kinds  ;  did 
they  shed  any  of  their  leaves  in  the  fall  ? 

9.  Are  the  leaves  that  remain   on   the  trees  living  ? 
Can  you  see  any  regularity  in  their  arrangement? 

10.  Are  the  leaves  grouped  the  same  way  in  different 
kinds  of  pines  ? 

ir.  Notice  the  pitchy  substance  under  the  bark  ;  what 
is  made  from  it  ? 

12.  Find  out  how  pitch,  turpentine,  rosin,  and  tar  are 
produced. 


AIR. 

A  common  and  interesting  application  of  the  facts  ob- 
served under  this  head  last  month  may  be  found  in  the 
so-called  suction  pump.  If  a  short  piece  of  tubing  from 
about  a  half  to  three-quarters  of  an  inch  bore  can  be  ob- 
tained, a  model  can  easily  be  constructed.  The  straight- 
sided  Argand  lamp  chimney  makes  an  excellent  tube  for 
this  purpose.  In  this  sized  tube,  the  working  of  the 
valves  may  be  seen.  For  these,  two  corks  will  be  needed  ; 
one  tightly  fitting  the  lower  end  and  one  passing  smoothly 
into  the  tube.  The  latter  may  be  made  to  fit  as  desired, 
by  wrapping  it  with  a  string.  Bore  a  small  hole  through 
the  corks,  and  to  the  upper  surface  of  each  fasten  by  one 
edge  a  thin  piece  of  leather  large  enough  to  cover  the 
hole.  This  may  be  done  by  drawing  a  pin  down  through 
it  and  clinching  it  on  the  under  side.  The  piston  rod 
may  be  made  by  twisting  together  two  wires,  leaving 
them  spread  at  one  end,  so  that  they  may  be  passed 
through  the  cork,  one  on  either  side  of  the  hole. 

The  Pump. 

1.  Why  are  the  valves  needed  in  a  pump  ? 

2.  Will  the  pump  work  if  the  lower  valve  is  placed 
some  distance  up  the  stock  ?     How  high  above  the  lower 
end  may  this  valve  be  located  ?     Recall  the  experiment 
with  the  mercury  last  month  to  explain  this. 


February]  PH.  YSICS.  231 

3.  What  is  the  use  of  the  piston  ? 

4.  By  what  means  does  the  water  reach  the  spout  of  the 
pump  after   it  passes  through  the  piston  valve  ?     What 
kind  of  a  lever  is  the  pump  handle  ?     In  the  force  pump 
there  is  no  valve  in  the  piston,  and  the  water  is  forced 
out  by  a  downward  movement  of  the  piston  through  an 
opening  between  it  and  the  lower  valve.     In  the  fire  en- 
gine the  water  is  thus  forced  into  an  air  chamber  by  two 
such  pumps,  and  to  this  the  hose  is  attached.     By  what 
means  is  the  water  forced  through  the  hose  ? 

5.  Can  you  see  any  advantages  in  forcing  the  water 
out  in  this  way  instead  of  lifting  it  as  in  the  suction 
pump  ? 

6.  What  is  the  advantage  of  the  air  chamber  ?    Recall 
the  various  properties  of  air  studied  in  January. 

7.  Where  should  valves  be  placed  in  the  force  pump 
of  the  fire  engine  ? 

8.  Is  the  flow  of  water  into  the  air  chamber  steady  or 
intermittent  ?      Compare  this   with   the    flow   from  the 
nozzle  of  the  hose  ;  can  you  account  for  the  difference  ? 

The  Siphon. 

1.  Bend  a  small  glass  tube  similar  to  the  one  used  in 
the  January  work  in  Physics  (the  same  one  will  do)  so 
that  the  two  arms  are  of  unequal  length.     Place  the  end 
of  the  shorter  arm  in  a  bottle  of  water  ;  apply  the  lips 
to  the  other  end,  and  by  suction  start  the  flow  of  water 
through  the  tube. 

2.  Can  you  give  a  reason  for  the  continuance  of  the 
flow  ? 

3.  Reverse  the  ends  and  start  the  flow  aga*in  ;  does 
it  continue? 

4.  Hold  the  tube  in  such  a  way  that  the  ends  shall  be 


232  NATURE  STUDY.  [February 

at   the    same    level    and    start   the    flow  ;  what    is    the 
result  ? 

5.  What  is  the  force  that  causes  the  water  to  begin 
flowing  through  the  tube  ? 

6.  Where  is  the  force  applied  ? 

7.  Try  tubes   that    have    arms   of    different    lengths  ; 
with  those  having  the  same  bore,  what  determines  the 
rate  of  flow  ? 

8.  What  is  the  force  applied  which  causes  the  flow  to 
stop  when  the  arms  are  of  the  same  length  ? 

9.  Where   is  this   force  applied  ?      What  is  there  to 
overcome  this  force  when  one  arm  of  the  tube  is  longer  ? 

10.  The  siphon  in  a  modified  form  is  much  used  in 
pumping  water  out  of  leaky  boats.     A  jet  of  steam  is 
admitted  at  the  elbow  and  forced  out  through  one  of  the 
arms  ;  by  doing  this,  water  may   be  made  to  flow  out 
through  the  short  arm.     Can  you  explain  why  this  is  so  ? 
Why  not  use  the  ordinary  form  of  the  siphon  in  pumping 
boats  ? 

11.  What  will  determine  the  greatest  length  that  the 
short  arm  may  be  in  the  ordinary  siphon  ? 

CAPILLARITY. 

1.  Examine  closely  the  surface  of  water   in  a  partly 
filled  glass  ;  is  it  exactly  level  ? 

2.  Dip  a  small  piece  of  glass  into  a  vessel  of  water  ; 
note  the  water  in    contact  with  the  glass.     Color  the 
water  with  a  little  red  ink. 

3.  Hold  two  small  plates  of  glass  together  along  two 
of  the  edges  so  that  the  faces  of  the  glass  will  be  but 
slightly  separated  ;  notice  the  water  between  the  pieces 
of  glass. 

4.  Cover  the  surfaces  of  a  piece  of  glass  with  grease, 


February]  PHYSICS.  233 

and  hold  upright   in   water  ;   is  the  water  the  same  as 
before  at  the  line  of  contact? 

5.  Hold  a  glass  tube  of  small  bore,  open  at  the  end, 
upright  in  a  vessel  of  water  ;  note  the  water  inside  the 
tube.     Try  tubes  of  very  large  and   very  small  bore  ; 
what  difference  between  them  ? 

6.  If  mercury  can  be  obtained,  repeat  the  above  exper- 
iments, using  it  in  place  of  the  water.      What  difference 
noted  ? 

7.  When  the  glass  surface  is  clean  in  the  above  exper- 
iments, does  it  become  wet  when  immersed  ? 

8.  Does  it  become  wet  when  smeared  with  grease  ? 
What  difference  noted  at  the  line  of  contact  in  the  two 


cases 


9.  Does  the  mercury  wet  the  glass  ?     Does  it  rise  or 
fall  at  the  point  of  contact  ? 

10.  The  water  is  said  to  rise  in  the  small  tubes  in  the 
above  experiments  by  capillary  attraction.     Capillary  is 
from  the  word  capillus,  meaning  a  hair.     It  is  so  named 
because  water  rises  best  in  the  slender  hair-like  tubes. 

11.  How  do  the  conditions   for   capillary    attraction 
differ  from  those  which  caused  water  to  rise  in  tubes  in 
previous  experiments  ? 

12.  Place  one  end  of  a  string  or  strip  of   cloth  in  a 
goblet  partly  full  of  water,  and  allow  the   other   end   to 
hang  over  on  the  outside.     Can  you  explain  what  takes 
place?     Is  the  rising  of  the  water  due  to  capillarity? 
Study  carefully  the  conditions. 

13.  Place  the  end  of  a  stick  in  a  vessel  of  water.    Can 
you  explain  why  it  becomes  soaked  ?     Why  does  water 
in  a  cask  prevent  the  hoops  from  becoming  loose  ? 

14.  How  does  the  oil  or  alcohol  in  a  lamp  reach  the 
upper  end  of  the  wick. 


234  NATURE  STUDY.  [February 

BUOYANCY  OF  LIQUIDS. 

1.  Tie  a  string  to  a  small  stone  weighing  about  half  a 
pound  and  note  carefully  the  weight  as  it  is  suspended 
from  the  finger.     Lower  it  into  a  vessel  of  water,  and 
note  the   difference   in   weight.     What  reason  can  you 
assign  for  the  difference  ? 

2.  Place  an  egg  in  a  tumbler  or  bucket  of   water  ; 
does  it  swim  or  sink  ?     Does  it  seem  to  have  lost  any 
weight  ? 

3.  Fill  another  tumbler  with   strong  salt  water,  and 
pour  it  slowly  into  the  one  containing  the  egg.     Can  you 
account  for  the  change  in  the  position  of  the  egg  ? 

4.  Half  fill  a  tumbler  with  water,  and  then,  by  means 
of  a  tube  reaching  to  the  bottom,  add  brine  until  the 
tumbler  is  full.     Drop  the  egg  in  cautiously  ;  does  it  go 
to  the  bottom  ? 

5.  In  what  part  of  the  tumbler  is  the  brine  ?    Why  add 
it  by  means  of  a  funnel  or  tube? 

6.  Suspend  a  small    stone   beneath  one  of  the  scale 
pans  of  a  balance  and  by  weights  in  the  other  pan  bal- 
ance it.     Now  hold  it  so  that  the  stone  is  completely 
immersed  in  a  vessel  of  water. 

7.  What  is  the  force  which  causes  the  opposite  scale 
pan  to  descend  ?     How  is  the  force  applied  ? 

8.  How  much  weight  must  you  add  to  the  scale  pan 
above  the  stone  to  make  the  two  sides  balance  ? 

Each  pupil  may  make  a  balance  which  will  answer  the 
purpose  very  well.  Use  a  small  stick  about  eight  inches 
long  for  the  beam.  By  means  of  three  threads  suspend 
from  each  end  the  scale  pans.  These  may  be  made  from 
a  piece  of  tin  two  inches  square  by  cutting  it  in  one 
quarter  of  an  inch  at  each  corner,  so  that  the  edges  may 


February]  PHYSICS.  235 

be  turned  up.  The  tin  caps  of  small  baking  soda  cans 
may  be  substituted.  Drive  pins  down  through  the  ends 
of  the  beam,  and  turn  them  up  for  hooks  from  which  the 
pans  may  be  suspended.  Drive  a  pin  upward  through 
the  middle  of  the  beam  by  which  the  balance  may  be 
supported.  Pass  another  pin  through  the  bottom  of  one 
of  the  scale  pans,  and  turn  it  up  to  form  a  hook  from 
which  the  stone  may  be  suspended.  Balance  the  two 
pans  by  using  fine  sand.  Small  shot  may  be  used  for 
weights.  Any  druggist  will  determine  the  number  of 
these  to  an  ounce  for  you. 

9.  Fill  a  tumbler  brimful  of  water  and  arrange  it  so 
that   the   overflow    may   be   caught    in    another   vessel. 
Suspend  a  small  stone  under  the  scale  pan  and  balance 
it.     Immerse  it  in  the  tumbler  of  water  and  balance  it 
again.     Weigh  the  overflow  of  water  when  the  stone  is 
completely  immersed.     How  does  the  weight  of  the  over- 
flow correspond  with  that  necessary  to  balance  the  scales 
after  the  stone  is  immersed  ?     Why  is  the  weight  obtained 
for  the  overflow  likely  to  be  somewhat  inexact  ?     Can 
you  see  from  the  experiment  what  the  lifting  power  of 
water  is  ? 

10.  The  weight  of  any  solid  or  liquid  compared  with 
the  same  bulk  of  water  is  its  specific  gravity. 

Weigh  a  stone  or  other  heavy  body  in  the  air,  and  then 
weigh  it  in  water  ;  the  weight  of  what  volume  of  water 
does  its  loss  in  the  latter  case  represent  ?  Recall  the 
experiment  performed  in  (9). 

11.  Compare  the  weight  of  the  body  in  air  with  the 
weight  of  the  volume  of  water  found  in  (10).     This  will 
give  its  specific  gravity. 

12.  Since  tin  is  heavy  enough  to  sink  in  water,  why  is 
it  that  a  tin  cup  will  float  ? 


236  NATURE  STUDY.  [February 

13.  Will  an  iron  pot  float  ?     If  broken  into  fragments, 
will  the  pieces  float  ? 

14.  How  is  it  possible  to  build  iron  vessels  that  will 
bear  heavy  cargoes  ? 

15.  If  a  cup  of  mercury  can  be  obtained,  try  to  sink 
'different  bodies  into  it,  such  as  stone,  iron,  etc.     Can 
you  explain  why  they  float  ? 

16.  Weigh  a  small  block  of  wood  ;  drop  it  into  a  ves- 
sel brimful  of  water,  so  placed  that  the  overflow  may  be 
caught  and  weighed  as  in  (9).     By  means  of  a  pin  stuck 
into  the  block,  push  it  down  just  beneath  the  surface. 

17.  Weigh  the  overflow  and  compare  with  the  weight 
of  the  block  ;  by  comparing  this  with  the  result  obtained 
in  (9),  can  you  explain  why  wood  will  float  and  iron  or 
stone  will  sink  ? 

PRESSURE  OF  LIQUIDS. 

1.  Take  a  tin  fruit  can,  or  one  similar  to  it,  and  in  one 
side  make  a  vertical  row  of  smooth  holes  an  inch  apart, 
each  large  enough  to  admit  a  large-sized  knitting  needle. 
Fit  them  with  smooth  pine  plugs. 

2.  Fill  the  can  with  water  and  remove  the  upper  plug  ; 
note  the  force  of  the  jet  and  the  distance  the  water  is 
thrown  out. 

3.  Fill  again  and  remove  the  second  plug.     Repeat 
until  the  flow  has    been    observed    from  each  opening 
separately  and  from  all  at  once. 

4.  From  which  opening  is  the  water  thrown  farthest  ? 
Upon  what  does  the  distance  that  it  is  thrown  depend  ? 

5.  Try  the  experiment  again,  using  cans  some  of  which 
have  larger  and  others  smaller  diameter,  but  of  the  same 
height.     The  holes  should  be  as  nearly  uniform  in  every 
respect  as  possible. 


February]  PHYSICS.  237 

6.  Repeat   the    experiment,    using   cans   of   different 
heights  ;  upon  what  does  the  force  of  the  jet  depend  ? 

7.  Is  the  force  of  the  jet  affected  by  the  volume  of 
water  in  the  can  ? 

8.  What  is  the  force  which  causes  the  water  to  issue 
in  the  jet  ?     In  what  directions  is  this  force  exerted  ? 

9.  Cut  a  circular  piece  of  cardboard  an  inch  and  a  half 
in  diameter  ;  drop  it  cautiously  on  the  surface  of  a  goblet 
of  water.     Press  down  upon  this  the  end  of  a  lamp  chim- 
ney (a  small  one  used  for  a  night  lamp  will  answer)  and 
push  the  cardboard  below  the  surface. 

10.  What  holds  the  cardboard  against  the  bottom  of 
the  chimney  ?     What  must  be  the  direction  of  the  pres- 
sure ? 

11.  Pour  water  cautiously  into  the  top  of  the  chimney- 
when  does  the  cardboard  fall  away  from  the  chimney  ? 
How  high  is  the  column  of  water  the  pressure  of  which 
holds  the  cardboard  in  place  in  the  first  instance  ? 

12.  Make   a   drawing  of   the   vessel    with  the   lamp- 
chimney  and  card   pushed   into  it,  and   show   by  arrows 
the  direction  the  lines  of  pressure  must  take  to  support 
the  cardboard  against  the  bottom. 

13.  Hold  a  cork  s,o  that  it  is  half-way  to  the  bottom  of 
a  goblet  of  water  ;  what  is  the  height  of  the  column  of 
water  that  is  pressing  it  downward  ?     What  is  the  height 
of  the  column  pressing  it  upward  ?     Why  does  it  rise 
when  you  let  go  of  it  ?     (Recall   17   under  Buoyancy  of 
Liquids.) 

14.  In  the  same  way  show  why  a  stone,  a  piece  of  lead 
or  iron,  must  sink  ? 

15.  Under  what  conditions  would  a  body  remain  sus- 
pended in  the  midst  of  a  vessel  of  water  ? 

16.  When  you  place  your  hand  at  the  bottom  of  a 


238  NATURE  STUDY.  [February 

bucket  of  water,  do  you  notice  the  weight  of  the  water 
on  top  ?  Would  you  feel  the  weight  if  the  bucket  of 
water  were  set  upon  the  top  of  your  hand  ?  How  do  the 
conditions  in  the  last  two  experiments  differ  ? 

17.  Why  is  it  that  fishes  can  live  and  can  swim  with 
ease  in  the  water  at  great  depths  ?  Why  do  they  become 
distended  when  brought  to  the  surface  ? 


CARBON. 

1.  Hold  a  piece  of  glass  or  a  plate  over  the  flame  of  a 
burning  candle  close  to  the  wick.     What  collects  on  the 
under  side  ? 

2.  Gather  a  little  of  the  substance  formed  in  (i)  and 
shake  well  in  a  bottle  or  test  tube  of  water  ;  is  it  solu- 
ble ? 

3.  Take  a  small  amount  of  sugar,  half  a  teaspoonful, 
and  heat  it  in  a  shallow  dish  or  spoon.     Examine  closely 
the  charred  mass  ;  is  it  sugar  ?     While  the  sugar  is  heat- 
ing, without  burning  with  a  flame,  hold  a  cold  glass  or 
porcelain  plate  over  it ;  what  gathers  on  the  surface  ? 

4.  What  kind  of  change   has  taken  place  ?      Is   the 
charred  substance  soluble  ? 

5.  Instead  of  the  sugar, use  a  small   piece  of  meat ; 
what  result  is  obtained  ? 

6.  Set  fire  to  a  piece  of  wood  ;  when  well  ablaze  ex- 
tinguish, and  notice  the  blackened  end. 

7.  Take  a  small  wad  of  paper,  and   heat  it  for  some 
time  in  a  test  tube  without  allowing  it  to  blaze ;  what 
kind  of  substance  remains  ? 

8.  Coarsely  powder  a  small  lump  of  soft  coal  and  half 
fill  a  common  clay  pipe.     Cover  the  mouth  of  the  bowl 
with  soft  clay  (plaster  of  paris  is  better)  and  place  it  in 
the  flame  of  the  lamp  upon  some  support,  with  the  stem 
projecting  upward. 

239 


240  NATURE  STUDY.  [February 

9.  Watch  the  end  of  the  stem  and  from  time  to  time 
apply  a  lighted  taper. 

10.  Can  you  tell  what  is  produced  from  the  coal  within 
the    pipe    bowl  ?     Note   the    odor   at    the  end    of    the 
stem. 

11.  What  does  the  flame  remind  you  of  ? 

12.  When  the  flame  dies  out,  remove   the  lamp  and 
allow  the  bowl  to  cool.     Then  remove  the  clay  and  ex- 
amine the  contents. 

13.  Has  there  been  a  change  in  the  coal?     Compare 
what  you  find  within  the  pipe  with  the  coal   with   which 
you  began. 

14.  Has  it  burned  to  ashes?     Does  it  remind  you  of 
anything  that  you  have  examined  in  a  previous  month  ? 
(See  Mineralogy   for    November.)     It    is   in    a   manner 
similar  to  this  that  coke  is  manufactured  on  a  large  scale. 
Very  large  ovens  are  constructed  and  are  lined  with  fire- 
brick.    There  is  one  opening  in  the  top  through  which 
the  oven  is  charged,  and  another  at  the  side  through 
which  the  coke  is  withdrawn.     After  the  coal  has  burned 
for  several  hours,  both  openings  are  closed  and  the  burn- 
ing is  completed  without  contact  with  air.     The  coke  is 
then  withdrawn  through  the  opening  in  the  side,  and  the 
oven  is  recharged.     The  heat  of  the  oven  is  now  suffi- 
cient to  start  the  burning  without  resorting  to  any  other 
means.     The  country  blacksmith  makes  his  own  coke 
usually  on  the  open  forge,  but  it  is  neither  so  easily  nor 
so  well  made  as  it  is  in  the  closed  oven. 

15.  Where  is  the  great  coke-producing  region  of  the 
United  States?     What  is  coke  used  for? 

16.  As  directed  above,  heat  a  pipe  half  filled  with  small 
bits  of  oak  wood  ;  can  you  get  a  flame  at  the  end  of  the 
pipe  stem  ? 


February]  CHEMISTRY.  241 

17.  How  does  what  remains  in  the  pipe  differ  from  the 
original  wood  ? 

Wood  charcoal  is  made  on  a  large  scale  by  placing 
sticks  of  wood  in  a  compact  pile  which  is  covered  first  with 
a  layer  of  straw  and  then  with  earth  and  turf.  Small 
holes  are  left  at  the  bottom  and  also  one  at  the  top. 
Through  the  latter  the  pile  is  ignited,  and  when  the  burn- 
ing is  well  started  the  opening  at  the  top  is  closed,  and 
the  pile  is  allowed  to  smokier  for  several  days  or  weeks, 
according  to  its  size.  Finally  the  holes  at  the  bottom  are 
closed  ;  after  the  fire  goes  out  the  pile  is  uncovered,  and 
the  wood  is  found  in  much  the  same  condition  that  you 
found  it  in  the  pipe. 

18.  Wet  a  small  wad  of  paper  with  ammonia  and  drop 
it  into  a  clean  bottle  ;  when  the  odor  of  ammonia  is  strong 
in  the  bottle,  remove  the  paper  and  drop  in  some  pow- 
dered charcoal.     Cork  and  shake  for  a  few  minutes  and 
note  the  odor.     Can  you  account  for  the  disappearance 
of  the  ammonia  gas  after  the  bottle  has  stood  for  some 
time  ?     The  charcoal  should  either  be  fresh  or  else  heated 
red-hot  and  cooled  under  a  glass  just  before  placing  in 
the  bottle  of  ammonia  gas. 

19.  Fold  a  small-sized  circle  of  filter  paper  and  place 
it  in  a  funnel.     Fill  it  two-thirds  full  of  powdered  char- 
coal.     Pour  upon  this  a  dilute  solution  of  indigo  ;  how 
has  it  been  changed  by  passing  through  the  charcoal  ? 
Try  some  vinegar  instead  of  the  indigo  solution.     Small 
filters  ready  cut  are  very  cheap,  and  may  be  obtained  from 
any  druggist.     Fold  it  first  in   halves,  then   in  quarters, 
then  in  eighths.     Press  the  creases  with  the  thumb  nail, 
but  avoid  touching  the  filter  between  them.    Open  it  up  and 
drop  the  pointed  end  into  the  funnel.    Pour  a  gentle  stream 
of  water  into  the  filter,  and  see  that  it  adheres  closely  to 


242  NA  TURE   STUD  F.  [February 

the    inner  surface  of  the  funnel.     It   is  then  ready  for 
use. 

20.  Can  you  see  any  reason  why  charcoal  is  used  in 
filters  and  as  a  disinfectant  ? 

21.  The  charcoal  obtained  in  the  foregoing  experiments, 
is,  as  was  learned  in  Mineralogy  for  November,  carbon. 
It  is  not,  however,  very  pure.     It  is  known  as  one  of  the 
chemical  elements  ;  that  is,  thus  far,  no  one  has  been  able 
to  separate  it  into  simpler  parts.     Other  forms  of  carbon 
are  the  diamond  (which  is  crystallized  carbon),  soot,  lamp- 
black, coke,  animal  charcoal,  graphite,  and  mineral  coal. 
The  formation  of  all  of  these  except  the  diamond,  graphite, 
and  coal,  is  somewhat   familiar  to  us.     It  will  be  remem- 
bered that  in  January  we  worked  out  the  history  of  a  fos- 
sil fern-leaf  which  was  found  imbedded  in  coal.     Further 
search  will  show  that  the  coal  contains  traces  not  only  of 
many  ferns,  but  the  remains  of  large  trees  and  stumps 
also.     In  fact  the  whole  coal  seam  has  been  shown  to  be 
the  remains  of  a  vast  bed  of  vegetation  that  was  buried 
as  the  fossil  fern  was,  and  with  it,  long  ages  ago.     Under- 
neath is  the  layer  of  clay  from  which  the  great  forest  of 
plants  grew.     Beneath  the  sediment  that  settled  upon  it, 
the  vegetable  mass  was  gradually  transformed  into  coal. 
Where  the  covering  was  porous  and  the  gases  that  were 
formed  escaped,  the  anthracite  was  formed  ;  where  the 
gases  were  retained  bituminous  coal  was  the  result.     It 
is  interesting  to  consider  to  what  extent  carbon  enters 
into  all  living  things.     The  story  of  how  it  does  so,  though, 
must  be  reserved  for  a  future  lesson. 

22.  Recall  experiment  (15)  under  Chemistry  for  Decem- 
ber ;  what  was  the  substance  in  the  jar  after  the  charcoal 
or  carbon  was  burned  in  it  ?    You  will  remember  that  a 
lighted  taper  would  not  then  burn  in  it,  although  it  did 


February]  CHEMISTRY.  243 

burn  very  freely  in  the  gas  O,  which  is  another  chemical 
element. 

23.  What  became  of  the  O  when  the  charcoal  was 
burned  in  it  ?     What  became  of  the  charcoal  or  carbon? 

24.  Where  did  the  new  substance  come  from  ?    Was  it 
a  solid  or  a  gas  ?     How  did  it  differ  from  O  ?     How  did 
it   differ  from  C   (carbon)  ?      The  new  substance  thus 
formed  by  the  burning  (which  was  nothing  but  the  two 
substances  forming  a  union)  is  carbon  dioxide  gas  (CO2) 
Recall  the  experiments  in  Chemistry  for  November  by 
which  this  substance  was  obtained.     The  explanation  of 
its  formation  then  will  be  given  at  another  time. 


Meteorology 

1.  Has  the  temperature  increased  or  diminished  since 
December  ?     Compare  February  with  January. 

2.  Is   the    temperature   increasing  or   diminishing  at 
present  ? 

3.  How  does  the  temperature  now  compare  with  that 
of  a  previous  month   in  which  the  days  were  about  the 
same  length  as  those  in  February  ? 

4.  Compare  the   rate  of  variation  in  temperature  this 
month  with  that  of  December  and  January  ? 

5.  What  is  the  direction  of  the  prevailing  wind  ?     Has 
it  been  a  cold  or  a  warm  one  ? 

6.  What  wind  has  preceded  rain  or  snow  storms  ? 

7.  Is  there  any  uniformity  in   the  veering  of  the  wind 
during  a  storm  ?     Can  you  see  a  reason  for  this?     Con- 
sult a  signal  service  map  ? 

8.  How  does  the  character  of  a  rain  in  this  month  differ 
from  one  in  the  summer  time  ? 

9.  How  does  the  amount  of  fogginess  compare  with  that 
of  previous  months  ?     When  do  they  appear,  if  at  all  ? 

10.  At  what  temperature  has  most  of  the  snow  fallen  ? 

11.  Has  rain  or  snow  been  most  frequent  this  month  ? 

12.  What  winds  have  been  accompanied  by  a  thaw  ? 

STUDY  OF  THE   WEATHER   BUREAU   MAPS. 

13.  Can  you  see  any  relation  in   position  or  as  cause 
and  effect  between  the  Low  Areas  and  the  place  of  heavi- 
est rainfall  ? 

244 


February]  METEOROLOGY.  245 

14.  Do  the  Low  Areas  lie  chiefly  in  the  same  region 
which  they  occupied  in  previous  months  ? 

15.  In  what  quarter  of  the  country  have  most  of  the 
great  storms  originated  this  month  ?     Compare  with  last 
month. 

1 6.  Which  way  do  the  storms  travel  ?    Have  there  been 
rain  and  snow  at  the  same  time  in  different  parts  of  any 
one  storm  ? 

17.  Is  there  any  uniformity  in  the  direction  of  the  wind 
in  these  great  storms  ? 

1 8.  What  is  the  direction  of  the  winds  with  respect  to 
the  High  Area? 

19.  Trace  a  line  through  the    most   southern    points 
touched    by  the  zero  isotherm.     How  does  its  position 
compare  with  that  of  last  month  ? 

20.  In  the  same  way  trace  the  snow  line,  and  compare 
with  January. 


Hetronom^ 

From  the  almanac  it  will  be  learned  that  Mercury  wil1 
appear  as  morning  star  February  6.*  This  planet  is  dis- 
tant from  the  sun  about  thirty-five  millions  of  miles  (see 
September),  and  has  a  diameter  one-third  that  of  the 
earth.  Its  time  of  revolution  is  about  eighty-eight  days. 

With  objects  to  represent  the  sun,  Mercury,  and  the 
earth,  it  will  be  interesting  to  study  the  relative  position 
of  the  three  bodies  at  different  times  during  the  year. 
A  diagram  on  the  blackboard  should  also  be  used,  and 
the  position  of  the  planets  Mercury,  Venus,  and  the 
earth,  as  seen  at  this  season,  should  be  marked  as  accu- 
rately as  possible.  New  figures  should  be  added  each 
month  which  will  show  how  their  positions  are  changing. 

1.  Why  is  it  that  Mercury  changes  from  morning  to 
evening  star  more  frequently  than  Venus  ? 

2.  Why  is  it  seen  as  either  morning  or  evening  star 
only  for  a  comparatively  short  period  ? 

3.  With   Mercury,  Venus,  and  the  earth  on  the  same 
side  of  the  sun,  and  in  a  straight  line  with  it,  what  will 
be  their  positions  at  the  end  of  one  month  ?     At  the  end 
of  Mercury's  year  ? 

4.  Will  Mercury  ever  be  visible  at  midnight  ? 

5.  Show  what  the  relative  position   of  the  earth,  sun, 
and  Mercury  is  when  the  latter  is  evening  star.      When 
it  is  morning  star. 

6.  Can  you  find  out  by  studying  the  rate  of  motion  of 

*  True  of  the  year  1891. 
246 


February]  ASTRONOMY.  247 

each    planet   how  often  it  will  be  either  a  morning  or 
an  evening  star  during  a  year  ? 

7.  In   which  of  the  preceding  months  did  the  day's 
length  correspond  to  that  of  this  month  ? 

8.  The  length  of  the  noon  shadow  on  the  measure  at 
the  present  time  corresponds  with  what  previous  month  ? 

9.  During  which  of  the  preceding  months  did  the  sun 
rise  and  set  at  about  the  same  points  on  the  horizon  that 
it  does  now  ? 

10.  Can  you  explain  why  at  two  different  seasons  there 
should  be  the  correspondence  noticed  in  the  observations 
suggested   by   the   last   three  questions  ?     Try  to  show 
this  by  using  the  globe  or  by  blackboard  diagrams. 

n.   Is  the  rate  of  variation  in  the  day's  length  increas- 
ing or  diminishing  this  month? 

12.  Compare  the  day's  length  at  Boston  or  New  York 
with  that  at  New  Orleans  ;  why  should  there  be  the  dif- 
ference noted  ?     Most  almanacs  give  the  length  of  day 
at  all  of  these  places. 

13.  Is  it  the  latitude  or  longitude  that  affects  the  day's 
length  ? 

14.  Is  the  day  increasing  in  length  at  both  places  at 
the  same  rate  ?     Why  does  the  rate  differ? 

15.  Is  the  difference  in  the  rate  of  variation  uniform 
throughout  the  month  ? 

16.  Can  you  by  any  observation  of  the  heavenly  bodies 
tell  in  what  direction  the  earth  moves  in  its  orbit  ? 

17.  Note  the  position  of  some  conspicuous  constella- 
tion, as  Orion,  at  a  certain  hour,  say  eight  o'clock  in  the 
evening.     Observe  its  position  during  the  month,  at  the 
same  hour  ;  is  it  always  the  same  ?     Explain. 

18.  Constellations. — In    addition  to  those  mentioned 
last  month,  Leo,  Cancer,  Canis  Minor,  and  Canis  Major 
may  be  given.     See  Clarke's  How  to  Find  the  Stars. 


(Beograpb^ 


EURO-ASIA.      RELIEF  AND  DRAINAGE. 

The  structure  of  this  great  land  mass  does  not  present 
the  same  simplicity  that  is  noticeable  in  the  double 
continent  of  the  New  World.  By  beginning  with  a 
consideration  of  the  rivers,  their  size,  and  their  direction 
of  flow,  a  fair  conception  of  the  principal  features  of 
relief  may  be  obtained.  The  many  strong  contrasts 
between  the  Old  World  and  the  New  World  which  are 
due  to  the  difference  in  direction  and  position  of  the 
great  highlands  should  be  carefully  considered.  The 
pupils  should  in  every  case  work  out  the  problems 
presented  by  means  of  map  modeling  and  by  use  of  the 
best  physical  maps  that  can  be  procured  for  reference. 
The  study  should  be  accompanied  by  stories  and  nar- 
ratives that  will  keep  the  conception  of  the  pupil  from 
being  narrowed  down  to  the  area  of  sand  in  the 
modeling  pan  before  him.  This  will  not  be  the  case  if 
sufficient  time  be  taken  to  work  in  such  pictures  of  the 
countries  as  may  be  obtained  from  the  many  good  books 
of  travel  of  the  present  time,  and  from  the  many  excellent 
magazine  articles  of  a  similar  kind.  Too  much  haste  on 
the  part  of  the  teacher  is  a  common  fault  with  many,  and 
it  is  a  most  serious  one.  The  conception  of  a  continent 
is  too  vast  in  its  scope  to  be  obtained  without  long  and 
careful  study. 

248 


February]  GEOGRAPHY.  *49 

1.  After  modeling  the    outline  of    the    land  mass  of 
Euro-Asia,  notice  the  direction  of    the  chief   highland 
region.     What    contrast  does   it  present  with    the  cor- 
responding great  highlands  of  America  ? 

2.  Note  its   position  in  the  land  mass  ;  in  this  respect 
does  it  present  similarity  or  contrast  with  the  New  World 
highlands  ? 

3.  What  is  the  direction  of  the  great  slope  of  the  con- 
tinent ?     Note  the  direction  of  the  longest  rivers. 

4.  What  ocean  receives   the  drainage  of  the  greater 
part  of  the  continent  ?    Compare  this  with  the  New  World. 

5.  Can  you  understand  why  the  drainage  waters  are 
not  gathered  into  a  very  few  great  river  systems,  as  in 
North  and  South  America  ? 

6.  On  which  side  of  the  great  highlands  are  the  greater 
river  systems  ?     Why  is  it  so  ? 

7.  North  of  the  great  highlands,  do  the  rivers  indicate 
any  secondary  water-partings  ? 

8.  Contrast   the  formation  of   river    systems   on  the 
opposite  sides  of  the  great  highlands.     To  what  is  the 
difference  due  ? 

9.  Note  the  direction  of  the  rivers  west  of  the  Ural 
Mountains  ;  what  does  it  indicate  as  to  the  surface  of 
northeastern    Europe  ?     From    what    other   region    do 
European  rivers  flow  ? 

10.  What  do  the   rivers  on  either   side   of   the  Ural 
Mountains  indicate  as  to  the  character  of  this  ridge?    • 

11.  From  the  general  direction  of  the  rivers,  can  you 
locate  the  highest  region  of  the  great  highlands  ? 

12.  Where  are  the  greatest  depressions  within  the  con- 
tinental outlines  ? 

13.  Are  there  any  rivers  in  Asia  that  do  not  reach  the 
sea  ?     Why  is  this  ? 


25°  NATURE  STUDY.  [February 

14.  In  how  many  directions  do  the  largest  Asiatic  rivers 
flow  ?     How  many   large   rivers  in  each   group  ?     Note 
those  on  the  north,  the  Obi,  the  Yenisei  and  the  Lena  ; 
on  the  east  the  Amoor,  the  Hoang-ho  and  the  Yang-tse- 
kiang  ;  the  Mekong  and  the  Irawaddy  on  the  southeast ; 
the  Brahmapootra,  the   Ganges   and   the    Indus  on  the 
south,  and  the  Amoo  Daria  and  Sir  Daria  flowing  into 
the  Aral  sea  on  the  west. 

15.  Contrast  this  grouping  of  the  rivers  with  those  of 
the  New  World  ;  what  is  the  cause  of  the  difference  ? 

16.  What  effect  does  the  position  of  the  highlands  have 
upon  the  development  of  Asia  ?     Why  is  the  effect  less 
marked  in  Europe  ? 

17.  What  effect  does  the  direction  of    the  highlands 
have  upon  the  development  of  the  continent  ?     Contrast 
it  in  this  respect  with  the  American  continents. 

1 8.  How  does  the  direction  in  which  the  great  rivers 
flow  affect  their  value  to  man  ? 

19.  Compare  the  great  plateaus  of  Euro- Asia  with  those 
of   the    New  World,  as  to  their    relation    to   the   great 
mountain  system. 

20.  Compare  the  position  of  the  highest  mountain  peaks 
of  Euro-Asia  in  the  great  highlands  with  these   in  the 
great  highlands  of  the  Americas. 

BOOKS  FOR    REFERENCE.     Guyot's  Physical  Geography.     Ritter's 
Comparative  Geography. 


Last  month  an  attempt  was  made  to  trace  the  history 
of  a  fossil  plant.  In  many  places  the  fossil  remains  of 
animals  are  more  abundant,  and  they  are  certainly  of 
equal  interest.  There  are  few  schools  in  which  at  least 
some  of  the  pupils  have  not  found  fossil  animals,  or  parts 
of  them,  and  they  may  be  made  available  for  the  whole 
school.  'The  history  of  such  fossils  must  be  worked  out 
along  much  the  same  line  as  that  followed  with  the  plant, 
but  the  different  environment  requires  a  little  modifica- 
tion of  treatment. 

The  way  in  which  animal  and  plant  remains  become 
buried  beneath  the  cloud  of  sediment  that  is  being  con- 
tinually thrown  down  on  the  floor  of  seas  and  lakes  may 
be  illustrated  by  stirring  into  a  jar  of  water  a  quantity  of 
fine  mud  or  sand  and  then  dropping  into  it  bones,  shells, 
water-soaked  sticks,  leaves,  etc.  When  the  silt  has  set- 
tled, pour  off  the  water  and  allow  the  sediment  to  be- 
come a  dry  cake.  Then,  by  cutting  or  breaking  it,  the 
bones,  etc.,  will  be  found  to  be  in  a  tightly-fitting  mold. 
Most  pupils  have  noticed  how  sticks,  etc.,  are  buried  by 
every  little  stream  in  its  sand  bars  and  in  the  mud  along 
its  banks. 

1.  Continue  the  observations  made  last  month  as  to  the 
depth  to  which  the  ground  is  frozen.     Is  it  frozen  to  a 
greater  depth  than  it  was  then  ? 

2.  If  it  is  possible  to  visit  a  quarry  or  an  exposed  ledge 

251 


252  NATURE  STUDY.  [February 

of  rock,  notice  whether  the  frost  is  causing  it  to  crumble. 
Can  you  find  any  rocks  that  have  been  split  by  freezing? 

3.  Notice  the  exposed  sides  of  ditches  or  hillsides  ;  can 
you   see  any  effects  of  freezing  ?     Does  vegetation  in- 
crease or  diminish  the  effects  of  frost  in  such  places? 

4.  Have  you  ever  found,  while  in  the  woods  or  else- 
where, the  remains  of  animals  that  have  died  ?     What  do 
you  think  must  become  of  these  after  a  time  ? 

5.  What  animals  have  you  found  thus  in  a  state  of  de- 
cay ?     What  parts  were  missing  ?     What  parts  will  last 
longest  ?     Have  you  ever  found  insects  in  this  condition  ? 
Have  you  ever  found  worms  or  birds  ? 

6.  Before  the  neighborhood  where  you  live  was  settled, 
do  you  know  what  wild  animals  lived  there  ?     What  be- 
came of  their  bodies  after  death  ?     Have  you  ever  found 
their  bones  ? 

7.  Do  you   know  of  animals  that  bury  their  dead  ? 
Think  of  some  of  the  accidents  that  might  cause  an  ani- 
mal to  be  covered  with  earth  soon  after  death.     Which 
would  be  more  favorable,  a  forest  or  desert  ? 

8.  Compare  the  chances  of  a  land  animal  with  those 
of  one  living  in  the  sea  for  being  accidentally  buried  soon 
after  death  ?     Which  is  more  likely  to  be  eaten  by  some 
other  animal  ? 

9.  Which  kind  of  animal,  land  or  water,  is  likely  to 
decay  the  more  rapidly  ?     Which  one  has  in  its  body  the 
most  material  that  will  tend  to  resist  decay  ?     What  are 
such  parts  ? 

10.  Have  you  ever  found  traces  of  any  kind  of  the  re- 
mains of  an  animal  ? 

n.  What  are  direct  proofs  you  have  that  such  traces 
are  the  marks  of  a  once  living  animal? 

12.  Can  you  tell  whether  it  was  a  land  or  a  water  ani- 


February]  GEOLOGY.  253 

mal?     Of  which  class  are  the  remains  most  abundant? 
Why? 

13.  What  animal  living  now  does  it  most  resemble  ? 

14.  If  it  be  the  remains  of  a  water  animal,  can  you 
imagine  something  as  to  what  its  surroundings  must  have 
been  ?     Did  it  live  in  sea,  lake,  or  river  ?     In  salt  or  fresh 
water  ? 

15.  Can  you  tell  whether  it  lived  in  deep  or  shallow 
water  ?     Was  it  clear  or  muddy  ?     What  other  evidence 
is  there  that  water  once  covered  the  region  where  it  was 
found  ? 

16.  Can  you  tell  what  range  of  temperature  the  water 
may  have  had  ? 

17.  Did  it  eat  ?     If  so,  what  must  have  been  its  food  ? 

18.  Did  the  animal  walk,  swim,  crawl,  or  was  it  fixed? 

19.  Did  it  have  an  inside  skeleton  or  an  outside  shell  ? 

20.  What  were  the  soft  parts  of  the  body? 

21.  Could  it   see  and   hear?      Do  you  see  anything 
which  would  show  whether  it  had  a  voice  or  the  power  of 
making  a  noise  ? 

22.  Can  you  tell  whether  there  were  many  more  ani- 
mals like  this  one  that  lived  at  the  same  time  ?     What 
way  could  you  prove  this  ? 

23.  Have  you  any  means  of  knowing  how  long  the  ani- 
mals lived  ?     Have  you  any  means  of  knowing  how  long 
the  water  may  have  covered  the  region  where  this  ani- 
mal lived  before  it  was  born  ?     How  would  you  look  for 
evidence  of  this  kind  ? 

24.  Can  you  tell  whether  it  lay  very  long  before  it  be- 
came covered  ? 

25.  By  what  process  do  you  think  it  was  covered  ? 

26.  Was  it  covered  gradually  or  suddenly  ?      By  fine 
or  coarse  material  ? 


254  NATURE  STUDY.  [February 

27.  Do  you  have  in  the  fossil  the  real  substance  of  the 
animal  tissues  ? 

28.  If  the  animal  tissues  are  not  present,  can  you  find 
any  evidence  as  to   whether  their  decay   was  slow  or 
rapid  ? 

29.  How   must  the  stony   substance   which   took  the 
place  of  the  tissues  have  been   deposited   there  ?     Is  it 
likely  it  was  deposited  there  before  the  animal  was  com- 
pletely buried  ? 

30.  Is  there  any  way  of  finding  out  whether  the  water 
remained  long  in  the  region  where  it  was  buried  ?     What 
would  the  amount  of  rock  and   earth  above  the  stratum 
in  which  the  fossil  was  found  indicate? 

31.  Is  there  any  way  by  which  you  could  determine 
whether  or  not   the  sea  revisited   the   region  where  the 
fossil  was  found  after  leaving  it  the  first  time  ? 

32.  Suppose  fossil  plants  were  to  be  found  in  strata  or 
layers  some  distance  above  the  stratum  where  the  fossil 
animal  was  found  ;  what  chapter  in   the  history  of  the 
region  would  that  unlock  ? 

33.  When  the  water  this  last  time  left  the  place  where 
the  fossil  was  found,  is  there  any  reason  to  believe  that 
the  surface  was  higher  than  it  is  now  ? 

34.  Can  you  find  any  evidence  as  to  why  the  water  left 
the  locality  where  the  fossil  was  found  ?     Was  the  ground 
uplifted  ? 

35.  If  the  ground  was  uplifted,  was  the  movement  slow 
and  gradual  or  rapid  and  violent  ? 

36.  What  changes  did  the  soft  material  in  which  the 
remains  of  the  animal  were  embedded  undergo  in  the 
course  of  time  ? 

37.  Was  the  substance  of  the   rock  melted  or  affected 
by  great  heat  after  the  animal  was  entombed  ? 


February]  GEOLOGY.  255 

38.  Can  you  think  of  any  conditions  which  surround 
animal  life  at  present   that  must  have  surrounded  this 
fossil  animal  while  living  ? 

39.  Can  you  think  of  any  conditions  present  now  which 
must  have  been  absent  at  that  time  ?    Which  may  have 
been  absent  ? 

40.  If  the  fossil  you  have  is  that  of  a  land  animal,  can 
you  tell  anything  of  its  habits  ?     Did  it  likely  live  on  an- 
imal or  vegetable  food  ?      What  part  of  its  body  that 
could  be  preserved,  would  be  the  most  useful  in  answer- 
ing this  question  ? 

41.  Was   it   warmer    or    cooler   than     now    when    it 
lived  ? 

42.  In  what  respects  must  the  history  of  a  land  fossil 
differ  from  that  of  an  animal  that  lived  in  the  water  ? 

43.  If  animals  like  those  whose   fossil   remains  have 
been   examined   do  not   exist   now,  can  you   assign  any 
reason  for  the  race  dying  out  ? 

44.  What  natural  change  in  conditions  can  you  imagine 
that  might  take  place,  which  would  tend  to  cause  certain 
of  our  living  species  of  animals  to  die  out  gradually,  not 
suddenly  ? 

45.  What  slight  change  would  affect  the  earthworms  ? 
What  would  affect  birds  ?     What  would  affect  fishes  ? 

46.  What  artificial  causes  are  removing  animals  from 
the  earth  ? 

47.  What  classes  of  animals  now   living  will  probably 
never  become  fossilized  ?     Is  it  possible  that  such  animals 
may  have  existed   when  the  fossil   you   have  examined 
lived  ? 

48.  Do  you  think  it  would  be  possible  for  soft  animals 
now  living,  such  as   earthworms,  to  leave  any  traces  of 
their  existence  as  fossils  ? 


256  NAJ'URE  STUDY.  [February 

49.  From  what  you  have  studied  about  fossils,  do  you 
think  fossilization  of  animals  and  plants  is  the  rule  or 
exception  after  death  ? 

BOOK  FOR  REFERENCE.  Humboldt  Library  :  No.  33,  Vignettes 
from  Nature,  chap.  viii. 


Last  month  certain  stones  were  examined,  some  of 
whose  properties  were  learned  by  means  of  acids.  Some 
additional  facts  may  be  learned  this  month  about  these 
same  stones  by  burning  or  roasting  them  in  the  fire. 

1.  Hold  a  small  piece  of  limestone  or  marble  in  the  flame 
of  the  lamp  till  red  hot  clear  through.     It  may  be  done  by 
using  pincers  or  by  means  of  a  wire  wrapped  around  it. 
Lay  aside  till  cool  and  moisten  with  water  ;  what  change 
takes  place  after  some  little  time  ?     The  rapidity  of  the 
change  depends  upon  the  variety  of  limestone  used. 

2.  What  is  thus  formed  ?     What  use  is  made  of  the 
substance  thus  obtained  ?     When  sand  is  added  and  the 
mixture  is  wet,  the  lime  and  the  silica  of  the  sand  unite 
and  form  a  strong  cement. 

3.  In  a  similar  manner  burn  a  piece  of  gypsum  ;  when 
cool  add  a  little  water  and  allow  it  to  stand  a  few  minutes. 
What  is  the  nature  of  the  substance  found  ?     Have  you 
seen  it  before  ?     For  what  is  it  used  ?     Why  is  it  called 
plaster  of  Paris  ? 

4.  Make  a  small  model  of  something  of  the  clay  used  in 
January  and  let  it  dry  partially.     Then  bum  it  thoroughly 
in  the  flame  of  the  lamp  ;  what  change  is  produced  ? 

5.  In  what  does  the  value  of  clay  for  manufacturing 
purposes   consist  ?      What    things   are    made   from   it  ? 
Where  is  it  found  ?     Pure  clay  is  white,  but  various  im- 
purities impart  different  colors  to  it  when  burned.     The 

257 


25 8  NATURE   STUDY.  [February 

redness  of  bricks  is  due  to  the  presence  of  iron  oxide,  a 
compound  of  iron  and  oxygen. 

6.  Treat  in  the  same  way  the  silicious   stones  that 
were  used  in  January  ;  compare  the  results  with  those 
obtained  above. 

7.  Make  a  full  comparison  of  the  two  classes  of  stones 
examined  during  January  and  February. 


Zoology 

This  month  is,  perhaps,  the  best  one  of  the  entire 
year  in  which  to  commence  the  study  of  outdoor  life. 
One  may  now  start,  as  it  were,  at  the  very  beginning, 
and  for  a  time,  if  his  wits  be  sharp,  keep  pace  with  the 
advancing  season  as  it  spreads  out  on  every  hand.  Every 
bright,  warm  day,  though  it  be  wedged  in  between  wintry 
ones,  is  pregnant  with  hope  to  all  things  that  live,  and 
the  natural  interest  of  the  pupils  should  be  properly 
encouraged.  Discouragement,  however,  is  all  too  easy, 
and  a  fruitful  source  of  it  is  in  much  of  the  science  read- 
ing of  the  schools.  A  great  deal  of  this  is  devoted  to 
the  so-called  "  wonders  "  of  nature,  and  when  the  pupil 
fails  to  see  anything  of  the  kind  about  him,  he  is  apt  to 
conclude  that  he  is  either  not  a  good  observer  or  that  he 
is  in  a  poor  locality. 

Two  things  should  be  kept  clearly  in  mind  :  first,  that 
what  is  read  in  any  one  book  is  not  the  result  of  one  man's 
observations  alone,  but,  usually,  that  of  very  many  people 
whose  successive  lives  have  covered,  perhaps,  hundreds 
of  years  ;  and  second,  that  the  truly  wonderful  things 
in  nature  are  rarely  the  violent  ones.  Not  the  flood,  the 
tornado,  the  lightning,  but  rather  the  gentle  rain,  the  soft 
breeze,  and  the  mild  but  life-giving  sunbeam,  have  made 
the  earth  what  it  is. 

No  one  locality  presents  all  of  the  interesting  things 
that  may  be  studied  in  nature  ;  it  is  equally  true  that  no 
locality  is  entirely  void  of  all  of  them.  It  may  be  said  that 

259 


260  NATURE   STUDY.  [March 

every  region  has  some  feature  that  will  make  it  distinct- 
ively an  interesting  place  of  study.  To  nature's  students 
her  treasures  are  equally  divided,  and  it  should  be  the  aim 
of  the  teacher  to  have  the  pupils  become  interested  in  the 
things  at  their  feet.  If  they  can  find  nothing  there 
worthy  of  their  study,  they  will  probably  fail  in  their 
search  wherever  they  go. 

The  pupils  should  be  impressed  with  the  necessity  of 
bestowing  great  care  upon  the  descriptions  which  they 
prepare  of  the  things  they  observe.  To  do  this  requires 
no  little  skill  on  the  part  of  the  teacher.  If  a  minutely 
detailed  description  is  insisted  upon  with  beginners,  the 
work  becomes  tiresome,  because  it  is  really  beyond  their 
powers  of  observation,  and  it  is  therefore  non-educative. 
What  is  meant  is  merely  this  :  whatever  is  really  seen, 
and  attempted  in  the  description,  should  be  clearly 
defined.  For  example,  if  the  color  of  a  bird  is  gray,  it 
should  be  stated  gray,  and  not  black  or  brown  ;  or,  if  it 
is  said  that  a  bird  walks  on  the  ground,  it  should  mean 
"  walk,"  and  not  hop.  Pupils  are  usually  anxious  to 
know  the  names  of  birds  and  other  animals  which  they 
have  seen.  Even  though  the  teacher  may  know  the 
name  perfectly  well  from  an  imperfect  description,  it 
should  be  a  rule  (to  which,  of  course,  there  may  be  judi- 
cious exceptions),  that  the  pupil  must  give  a  description 
sufficiently  accurate  to  enable  any  one  to  recognize  it  at 
sight,  if  he  be  familiar  with  the  terms  used.  A  pupil  who 
does  not  have  sufficient  interest  and  enterprise  to  do  that 
much  work  for  the  sake  of  the  name  he  desires,  would  be 
very  little  benefited  if  it  were  given  him  outright.  He 
must  feel  from  the  first  that  he  will  not  be  permitted  to 
get  something  for  nothing  ;  that  if  he  would  have  a 
return  he  must  first  make  an  investment. 


March] 


ZOOLOGY. 


26: 


This  month  a  calendar  should  be  provided  in  which  the 
pupils  can  record  their  observations  as  the  season  ad- 
vances. It  should  be  large  enough  to  admit  of  the  record 
being  made  without  crowding,  and  the  writing  should  be 
in  a  clear,  bold  hand.  As  a  convenient  form,  the  follow- 
ing model  is  suggested.  If  a  frame  with  glass  be  pro- 
vided, with  a  hinged  back,  it  will  be  kept  cleaner,  and 
will  present  a  neater  appearance.  In  this  may  be  re- 
corded the  times  of  the  return  of  birds,  the  first  flowers, 
etc. 

NATURAL   HISTORY   CALENDAR. 

189 — . 


OBSERVATION. 

DATE. 

PLACE. 

BY  WHOM. 

REMARKS. 

GENERAL  OBSERVATIONS. 

i.  Does  animal  life,  this  month,  give  any  indications  of 
returning  spring? 

.  2.  Have  you  noticed  any  frogs,  toads,  or  other  animals 
that  hibernate  during  the  winter  ?  Do  they  show  any 
effects  of  their  long  sleep  and  fast  ? 

3.  Have  any  of  the  birds  which  migrated  last  spring 
returned  ?     Have  any  of  the  birds  which  visit  us  during 
the  winter  disappeared  ? 

4.  Do  the  returning  birds  come  in  flocks,  in  pairs,  or 
singly  ?     Can  you  tell  whether  the  first  ones  that  come 
are  the  young  or  the  old  birds  ? 


262  NATURE    STUDY.  [March 

5.  Do  the  males  or  females  come    first?      What   do 
these  birds  do  if  overtaken  by  a  cold  snap  ? 

6.  What  is  the  food  of  the  birds  that  return  earliest  ? 

7.  Do  they  immediately  begin    nest-building  ?      Can 
you  tell  whether  or  not  they  repair  the  old  nests  ? 

8.  What  are  the  most  serious  dangers  that  threaten  the 
birds  that  first  return  ? 

9.  Do  the  returning  birds  seem  to  be  as  numerous  as 
those  that  migrated  last  fall  ? 

10.  Have  they  changed  their  plumage  ?     Do  the  birds 
sing  ? 

11.  What  kinds  of  insects,    if   any,    are   abroad   this 
month  ?     Study  their  habits.     Where  do  they  live  ? 

12.  Upon  wh'at  do  they  depend   for  food  ?     In   what 
way  are  they  adapted  to  getting  it  ? 

13.  Are  they  the  prey  of  any  other  animals  ?     Upon 
what  do  they   rely   for  safety,  defense,  concealment,  or 
flight  ? 

14.  Examine  some  of  the  cocoons  that  were  spun  last 
fall,  and  may  now  be  easily  seen  upon  twigs  of  trees  and 
bushes  ;  are  there  any  signs  of  life  about  them  ? 

15.  Observe  some  of  the  ant-hills,  or  other  haunts  of 
ants,  that  were  noticed  last  fall  ;  are  there  any  signs  of 
activity  ? 

1 6.  Have  you  seen  any  of  the  work    of  earthworms 
this  spring  ?     Can  you  find  any  near  the  surface  ? 

THE   CIRCULATION. 

T.  Place  two  fingers  of  the  left  hand  over  the  region 
of  the  pulse,  in  the  wrist  of  the  right  arm,  and  count 
the  pulsations.  Take  the  average  per  minute  for  five 
minutes. 

2.  Place  the  fingers  in  the  region  of  the  temples,  a  lit- 


March]  ZOOLOGY.  263 

tie  in  front  of  and  above  the  ear,  and  count  the  pulsa- 
tions felt  there.  Compare  with  the  number  felt  in  the 
wrist. 

3.  Rise,  and  count  again  in  a  standing  position. 

4.  Take  vigorous  exercise  of  some  kind  for  a  minute, 
and  count  again.     Place  the  fingers  about  the  middle  of 
the  chest,  a  little  to  the  left  of  the  breast-bone  ;  can  you 
notice  pulsations  there  ? 

5.  Do  you  notice  any  correspondence  between  the  pul- 
sations of  the  chest  and   the   wrist  ?     Between  those  of 
the  wrist,  temples,  and  chest  ? 

6.  When   were  the  pulsations  slowest  ?     When    most 
rapid  ? 

7.  Does  the  number  of  respirations  increase  with  vig- 
orous exercise  ? 

8.  The  pulsations  felt  in  the  chest  are  due  to  the  al- 
ternate contraction  and  expansion  of  the  heart.     Each 
contraction  forces  a  quantity  of  blood  out  into  a  set  of 
slightly  elastic   tubes   called    arteries.      These   are   dis- 
tended each  time  they  receive  the  blood,  and  in  conse- 
quence a  pulsation  is  felt  wherever  the  artery  lies  near  the 
surface. 

9.  Cross   the    legs   so   that   one   knee  rests  over  the 
other  ;  notice   the  toe  of  the  foot  uppermost  ;  can  you 
explain  why  it  cannot  be  held  perfectly  still  ? 

10.  From  your  own  observations,  can   you  tell    how 
exercise  affects  the  blood-flow  ? 

11.  What  effect  has  violent  exercise  upon  the  appear- 
ance of  one's  face  ?     Can  you  explain  this  ? 

After  passing  through  the  arteries,  the  blood  enters  a 
dense  network  of  very  minute  tubes  called  capillaries. 
While  the  blood  passes  through  the  capillaries,  important 
transfers  take  place.  The  nutriment,  digested  in  the 


264  NATURE    STUDY.  [March 

alimentary  canal,  and  received  into  the  circulation  by 
the  capillaries  and  other  absorbent  vessels  which  lie  in 
its  walls,  now  passes  out  to  renew  the  tissues  by  soaking 
through  the  walls  of  these  minute  vessels.  At  the  same 
time,  waste  materials,  dissolved  in  the  fluids  which  bathe 
the  tissues,  soak  through  the  walls  into  the  blood,  and 
are  carried  to  the  organs  of  excretion — the  lungs,  kid- 
neys, and  skin.  How  do  we  know  that  the  blood  circu- 
lates ?  This  is  by  no  means  an  easy  question,  or  it 
would  not  have  taken  so  many  centuries  for  wise 
men  to  find  out  the  fact.  Two  hundred  and  fifty 
years  ago  it  was  not  only  unknown,  but  the  idea  was 
ridiculed. 

12.  Note  the  blue  veins  lying  just  under  the  skin  ; 
have  you  any  proof  that  blood  is  flowing  through  them  ? 
Which  direction  ? 

13.  Hold  the  hand    loosely  downward  and  shake  it 
gently  ;  how  do  the  veins  change  in  appearance  ? 

14.  Hold  the  hands  above  the  head,  and  shake  them  in 
the  same  way  ;  what  difference  is  noticed? 

15.  While  holding  the   hands  downward  as   in   (12), 
press  with  a  finger  on  a  vein,  and  slip  it  toward  the  fin- 
gers ;  note  carefully  the  appearance  where  the  veins  fork. 
Small  pocket-like  valves  are  placed    here  to  prevent  a 
backward  flow  of  blood.     Can  you  tell  in  which  direction 
they  prevent  the  blood  flow  ? 

T6.  From  the  capillaries  (see  10)  the  blood  passes 
through  the  veins  to  the  right  half  of  the  heart,  and 
thence  to  the  lungs,  where  it  enters  the  capillaries  of 
these  organs.  (See  Respiration.)  From  the  lungs,  the 
blood  returns  to  the  heart,  the  left  half,  and  is  forced  out 
into  the  arteries  again,  which  carry  it  to  the  system. 

17.  Wrap  a  string  tightly  around  a  finger  about  an 


March]  ZOOLOGY.  265 

inch  from  the  end  ;  can  you  tell  why  it  swells  up  and 
changes  color? 

18.  With  a  pin,  or  needle,  make  a  slight  prick  through 
the  skin,  and  draw  a  large  drop  of  blood.     This  opera- 
tion is  not  painful  in  the  least. 

19.  Is  the  blood  perfectly  fluid  ? 

20.  Do  not  disturb  it  for  some  time,  but  closely  ob- 
serve any  changes  that  may  take  place. 

21.  Note  the  clot  that  forms;    does  the   entire  drop 
become  solid  ? 

22.  The   matter    that    becomes   solid    in   the   clot  is 
called  fibrin  ;  the  part  that  remains  liquid  is  the  serum. 
How   does   the   serum   differ   in   appearance   from   the 
blood  ? 

23.  If  the  drop  is  large  enough,  transfer  the  clot  to  a 
clean  piece  of  glass,  and  move  it  about  with  a  pin  in  a 
little  clean  water  ;  does  any  of  it  wash  away  ?     In  this 
way  the  solid  fibrin  may  be  separated  from  the  red  color- 
ing bodies  of  the  blood  called  corpuscles. 

24.  A  large  quantity  of  fibrin  may  be  easily  obtained 
thus  :  Catch  a  basin  of  blood  in  a  butcher   shop  from 
a  freshly  killed  animal,  and  with  a  bundle  of  twigs  or 
wires  whip  it  vigorously  for  a  few  minutes.     The  fibrin 
will  collect  in  a  stringy  mass  on  the  sticks  from  which  it 
must   be   removed,  and   then   thoroughly  washed   until 
freed  from  the  red  corpuscles.     This  may  then  be  pre- 
served indefinitely  in  alcohol  for  class  use. 

25.  Is  the  clotting  of  blood  of  any  importance  to  ani- 
mals? 

26.  What  effect  does  a  brisk  rubbing  of  the  surface  of 
the  body  have  upon  the  circulation  ? 

27.  How  does  a  hot  bath  affect  the  circulation  ?    How 
does  cold  water  affect  it  ? 


266  NATURE   STUDY.  [March 

28.  In  case  of  headache  from  over-study,  which  would 
be  more  apt  to  afford  relief,  a  hot  or  a  cold  foot-bath  ? 
Why? 

29.  Why  will  cold  water  sometimes  relieve  a  headache, 
and  at  other  times  hot  water  ? 

30.  What  animals  can  you  name  that  you  are  sure  have 
red  blood  ?     Do  you  know  of  any  without  it  ? 

31.  Examine  the  pulse  of  a  young  child,  and  also  that 
of  an  old  person  ;  what  differences  do  you  notice  ?    Com- 
pare with  your  own. 

32.  Compare  your  own  pulse  with  that  of  your  friend's, 
of   about   the   same    age  ;  note   both    the    rapidity  and 
strength  of  the  beat.     At  first  you  may  not  be  able  to 
detect  any  difference,  but  a  practiced  physician  would 
probably  find  no  two  exactly  alike. 

33.  Place   the  ear  near  the  body  of  a  dog  ;  can  you 
locate  the  heart  ?     Does  the  rate  of  beating  depend  upon 
the  size  of  the  animal  ? 

34.  In  the  same  way  examine  a  cat,  a  horse,  a  cow,  or 
any  other  animal  you  may  have  opportunity  to  observe. 

The  time  has  come  when  every  teacher  must  make  a 
demand  upon  his  school  board  for  a  microscope  for  his 
school.  No  similar  outlay  will  give  the  teacher  such  a 
vast  increase  in  power  to  interest  and  instruct  his  pupils. 
Its  use,  within  the  past  few  years,  has  revolutionized  our 
notions  concerning  the  nature  of  most,  if  not  all  dis- 
eases, and  it  has  done  more  to  place  the  practice  of 
.medicine  upon  a  scientific  basis  than  anything  else  since 
the  demonstrations  of  Harvey.  Without  its  use  it  is 
absolutely  impossible  for  the  pupils  to  get  any  but  the 
most  vague  conceptions  of  the  extreme  delicacy  of  those 
parts  of  the  body  that  are  concerned  directly  in  the  vital 
processes,  and  consequently  need  the  greatest  care. 


March]  ZOOLOGY.  267 

Believing,  therefore,  that  before  the  usefulness  of  this 
book  is  outlived,  very  many  teachers  will  have  one  at 
their  command,  the  following  directions  for  showing  the 
circulation  of  the  blood  are  given.  The  manipulation  of 
the  microscope  for  school  purposes  can  be  learned  in  ten 
minutes  from  a  book  that  is  generally  sent  with  the  out- 
fit, and  no  teacher  should  hesitate  because  he  has  had 
no  previous  instruction. 

(a)  Procure  a  small  tadpole,  and  place  it  under  a  wet 
cloth  on  a  strip  of  glass.     Allow  the  end  of  its  tail  to  pro- 
ject, and  cover  it  with  another  thin  piece  of  glass.    Keep 
moist,  and  examine  with  an  inch,  three-quarter,  or  a  half- 
inch  objective.     This  observation  is  of  historic  interest. 
About  two  hundred  and  twenty-five  years  ago,  by  this 
means,    the  circulation  of  the   blood  became  a  demon- 
strated   fact.     This  occurred  ten  years  after  Harvey's 
death. 

(b)  Procure  a   small  water-newt  (lizards  the  children 
will  call  them),  having  external  fringe-like  gills  near  the 
mouth.     Place  in  a  watch-glass  of  water,  and,  as  he  lies 
still,  watch  the  pulsating  currents  through  the  looped 
vessels    in   the    gills.     It  is  indescribably  beautiful.     A 
very  young  tadpole  will  do  as  well  for  the  purpose. 

(c)  Allow  a  hen  to  sit  upon  some  eggs  for  four  or  five 
days.    Perforate  with  a  pin  the  large  end  of  one  of  them. 
Break  away  the  shell  from  the  upper  side,  making  a  hole 
as  large  as    possible  without  disturbing   the   contents. 
Remove   the  membrane  and   examine  the  delicate   net- 
work of  blood  vessels  that  is  exposed.     Use  direct  light 
from  above.     Look  for  the  pulsating  heart.     It  is  safe  to 
leave  the  description  of  this  beautiful  sight  to  the  ob- 
server. 

(d)  Procure  a  live  frog  and  wrap  it  in  a  wet  cloth,  ex- 


268  NATURE   STUDY.  [March 

posing  one  hind  foot.  Tie  it  to  a  thin  strip  of  wood 
three  inches  wide.  By  means  of  thread  tied  to  the  toes, 
spread  them  so  that  the  web  will  be  somewhat  stretched, 
and  then  fasten  it  over  a  hole  in  the  board,  that  the 
light  may  be  reflected  upward  through  it  from  a  mirror. 
Keep  moist.  This  is  a  little  more  difficult  to  manage 
than  those  given  above. 

(e)  In  the  instances  above  given  the  blood  will  appear 
colored.     Procure  a  small  spider  with  semi-transparent 
legs.     Confine  it  lightly  between  two  glass  slips.     You 
will  be  able  to  follow  a  single  corpuscle  clear  down  his 
leg  to  his  "toes"  and  back  again.    It  looks  like  a  pebble 
being  rolled  and  pitched  along  by  a  current.     Can  you 
detect  color  in  the  blood  ? 

(f)  A  little  later  in  the  spring  procure  a  very  young 
crawfish.    You  can  hardly  fail  to  find  a  mother  "  craw  " 
with  hundreds  of  the  little  fellows  clinging  to  her  swim- 
merets.    Confine  him  very  carefully  as  directed  above, 
and  examine.    You  can  see  the  corpuscles  chasing  each 
other  all  through  the  body,  legs,  and  antennae  or  feelers. 
A  marvelous  thing  to  behold  ! 

REFERENCE.    Humboldt  Library  :  No.  48,  Life  in  Nature. 


During  this  month  the  pupils  should  be  alert  for  the 
first  evidences  of  spring  that  appear  in  plants.  If  the 
observations  indicated  in  the  previous  months  have  been 
made,  they  will  be  ready  to  notice  the  earliest  changes 
that  occur.  The  character  and  tendency  of  the  lessons 
should  be  to  lead  the  pupils  in  the  end  to  a  thoughtful 
consideration  of  nature's  great  miracle  wrought  in  this 
spring-time  renewal  of  life.  The  opening  of  a  bud  is  a 
matter  of  common  observation,  and  yet  it  cannot  be  said 
to  be  a  simple  or  commonplace  thing.  It  is  the  result  of 
causes  both  near  and  remote,  many  of  which  are  apt  to 
escape  unnoticed.  The  opening  of  the  buds  and  the 
sprouting  seeds  that  may  soon  be  seen  are  a  verification 
anew  of  every  law  in  nature's  code.  The  persistence  for 
ages  of  certain  plants,  cultivated  and  wild,  in  different 
latitudes,  furnishes  strong  proof  of  the  uniformity  of 
these  laws  in  their  operation.  The  distribution  of  the 
vine,  olive  and  fig,  for  example,  in  Europe,  would  indicate 
that  the  climate  has  remained  almost  absolutely  un- 
changed for  a  great  length  of  time.  It  is  said  that  a 
change  of  one-half  of  a  degree  in  the  mean  annual  tem- 
perature would  seriously  affect  the  growth  of  these 
plants,  and  render  their  cultivation  difficult,  perhaps  im- 
possible, in  regions  where  they  now  flourish.  There 
could  hardly  be  a  finer  illustration,  either  of  the  sensi- 
tiveness of  the  plants  to  their  environment,  or  of  the 

269 


27<>  NATURE   STUDY.  [March 

marvelous  balance  among  those  conditions  which  com- 
pose  it. 

The  observations  made  on  the  waking  plant  should  be 
accurate  and  systematic,  within  the  capacity  of  the  pupils, 
and  a  record  of  the  changes  ought  to  be  kept.  Each 
pupil  should  be  required  to  select  a  tree  conveniently  lo- 
cated for  daily  study.  In  connection  with  this,  a  study 
of  the  wood,  bark,  mode  of  branching,  etc.,  may  be  pur- 
sued before  the  buds  are  far  enough  advanced  to  require 
much  attention. 

1.  Make  a  drawing  of   the  tree  selected    for  study, 
being  careful  to  have  the  different  parts  in  proper  pro- 
portion. 

2.  Is  the  general  figure  of  the  tree  symmetrical,  as  you 
view  it  from  all  sides  ? 

3.  Can  you  notice  any  difference  between  the  north 
and  the  south  sides?     Between  the  east  and  the  west 
sides  ? 

4.  Do  trees  that  grow  in  the  woods  modify  or  change 
each  other  in  shape  ? 

5.  Can   you   tell   what  determines    the    height  above 
ground  at  which  a  tree  begins  to  branch  ?      Compare 
trees  that  are  isolated  with  those  of  the  same  kind  in 
forests. 

6.  What  variation  do  you  notice  in  the  shapes  of  the 
tops  of  different  trees  ? 

7.  What  seems  to   determine   the  shape  of  the  top  ? 
Compare  the  shape  of  a  pine  tree  with  that  of  an  apple 
tree  ;  all  stems  like  the  former  are  called  excurrent,  and 
all  like  the  latter  are  deliquescent.     Excurrent  means,  lit- 
erally, running  out ;  deliquescent  means  melting  or  dis- 
solving ;  can  you  see  the  force  of  these  meanings  when 
the  terms  are  applied  to  tree  tops  ? 


March]  BOTANY.  271 

8.  What  peculiarities  of  growth  give  rise  to  these  two 
forms  of  tree-tops  ? 

9.  Woody  plants  fifteen  or  twenty  feet  in  height,  or 
under,  are  called  shrubs ;  above  this  height,  trees.     Will 
all  shrubs  become  trees  if  allowed  to  grow  ? 

10.  Can  you  by  examination  determine  the  extent  to 
which  the  roots  of  a  tree  spread  ?     Compare  with  the 
spread  of  the  top. 

u.  The  main  stem  or  trunk  of  a  tree,  and  the  root 
growing  straight  downward,  are  sometimes  called  the 
axis  of  the  plant.  The  stem  is  the  ascending,  and  the 
roots  the  descending  axis.  Is  there  a  clearly  marked 
plane  of. division  between  the  ascending  and  descending 
parts  ? 

12.  Procure  a  piece  of  a  branch  two  or  three  inches  in 
diameter,  and  make  a  study  of  the  wood.     Can  you  tell 
in  what  part  of  the  branch  the  oldest  wood   is  to  be 
found  ?     When  is  the  new  wood  added  ? 

13.  Make  two  drawings,  one  of  a  cross,  and  the  other 
of  a  longitudinal  section. 

14.  The  wood  may  usually  be  distinguished  as  heart- 
wood,  or  duramen;  and  sap-wood,  or  alburnum.     Can  you 
distinguish  the  two  kinds  in  your  specimen?     What  are 
the  differences  between  them? 

15.  What  causes  the   circular  markings  that  may  be 
seen  in  a  cross  section  ?     Are  they  alike  on  all  sides  of 
the  branch  ?    What  will  affect  the  thickness  of  the  rings? 
Compare  the  upper  and  lower  halves  of  a  branch.     The 
north  and  south  sides  of  the  stump  of  a  tree.     Which 
ring   was    formed    last  ?    Notice   the    soft   spongy  sub- 
stance  in    the   center   of   the    twig    called    pith  ;    what 
is   the    shape    of    a     cross    section    of    the    pith-tube? 
How  does  it  differ  from  the  wood  ?     Split  a  twig  care- 


2?2  NATURE   STUDY.  [March 

fully  out  to   the   terminal   bud ;    does   the   pith   reach 
the  bud? 

16.  Notice  any  radial  markings  that  may  be  seen  in  a 
twig  ;  does  any  one  cross  more  than  one  ring  ?    Are  they 
found  in  the  bark  ?     These  lines  are  called  medullary 
rays. 

17.  Split  the  twig,  and  try  to  discover  the  structure  of 
the  medullary  rays.     Compare  the  wood  found   in  the 
rays  with  that  about  them. 

18.  Can  you  see  these  rays  in  any  of  the  articles  of 
furniture  about  you  ?     How  must  the  wood  be  cut  to 
show  them  to  advantage  ?    How  do  painters  imitate  their 
appearance  ? 

19.  Can  you  see  any  pores  in  the  wood  ?    Wet  one  end 
of  a  dry  piece,  and  try  to  blow  through  it  from  the  other  ; 
is  there  any  evidence  that  the  air  passes  through  ?     Are 
the  pores  openings  into  continuous  tubes  ? 

20.  Compare  the  bark  on  the  trunk  of  the  tree  with 
that  found  on  the  twigs  ;  are  there  the  same  layers  in 
both  ?     What  happens  if  the  bark  be  removed  down  to 
the  wood  ? 

21.  How  does  the  bark  differ  from  the  wood  ?     How 
is  it  joined  to  it  ?     Is  there  a  distinct  division  between 
them  ? 

22.  On  the  twigs,  the  layers  usually  found  are  the  cor- 
tex, or  cortical  layer,  which  is  the  dark  outer  covering ; 
the  green  layer  immediately  under  it,  and  the  liber  next 
the  wood.     Are  these  all  present  in  the  older  twigs  and 
in  the  tree  trunk  ?     Find  out  why  the  name  liber  is  given 
to  one  layer  ?    What  use  is  made  of  the  cortical  layer  in 
some  trees  ? 

23.  The  specks  often  to  be  found  in  the  bark  of  twigs 


March]  BOTANY.  273 

are  called  lenticels  ;  how  are  they  formed  ?     Is  their  ar- 
rangement regular? 

24.  Make  a  careful  examination  of  the  entire  tree  this 
month,  and  be  ready  to  note  the  first  changes  that  occur 
in  the  spring. 


LIGHT. 

In  beginning  the  study  of  light,  it  is  of  first  import- 
ance that  an  extended  series  of  simple  experiments  be 
devised  which  will  clearly  illustrate  the  fundamental 
principles  of  the  subject.  The  observations  and  experi- 
ments may  be  made  in  such  a  way  as  to  arouse  the  deep- 
est interest  on  the  part  of  the  pupil,  and  the  best  thought 
of  which  he  is  capable.  The  principles  underlying  the 
subject  are  comparatively  few,  and  may  be  stated  in  the 
simplest  language  ;  but  their  application  is  so  varied  and 
far-reaching  that  nothing  but  a  great  abundance  of  simple 
illustrative  experiments  in  the  beginning  will  ever  make 
them  clear.  Teachers,  here,  if  anywhere,  are  apt  to  make 
the  fatal  mistake  of  supposing  that  a  glib  statement  of  a 
principle  implies  mental  possession  of  the  concept  it 
embodies.  Space  will  not  admit  of  a  sufficient  number 
of  observations  and  experiments  being  described,  in  this 
connection,  to  make  the  subject  clear  ;  but  such  have 
been  selected  as,  it  is  believed,  will  best  indicate  to  the 
teacher  the  kind  of  work  that  should  be  done. 

The  apparatus  needed  is  simple,  cheap,  and  easily  ob- 
tained. It  is  necessary  to  darken  the  room  for  some  of 
the  observations,  and  the  teacher  should  be  able  to  do 
this  quickly.  If  the  windows  are  provided  with  solid 
shutters,  there  is  no  difficulty  :  but  if  there  be  slats  in 

274 


M  arch]  PH  YS1CS.  275 

the  shutters,  the  end  can  be  attained  by  tacking  over 
them  light-proof  paper  of  some  kind.  A  small  hole,  half 
the  diameter  of  a  lead  pencil,  in  an  east,  south,  or  west 
window,  will  admit  a  beam  of  sunlight  that  can  be  util- 
ized in  a  variety  of  interesting  ways.  Where  there  are 
no  shutters,  curtains  may  be  substituted  with  but  little 
trouble.  A  small  looking-glass  and  a  lamp  reflector, 
that  may  be  obtained  at  any  lamp  store  at  small  cost, 
will  be  needed  in  a  study  of  reflection.  For  a  lens,  the 
magnifying  glass  used  in  botanical  work  will  answer. 
Directions  were  given  in  the  September  work  for  making 
a  suitable  prism. 

r.  Why  is  it  (without  considering  the  eye)  we  can  see 
an  object,  such  as  a  book,  in  the  room  in  daylight,  but 
cannot  see  it  in  the  darkness  at  night? 

2.  Why  is  it  that  we  can  see  it  after  dark,  if  a  lighted 
lamp  is  brought  into  the  room  ?     In  seeing  the  book, 
does  the  light  first  pass  from  the  lamp  to  the  eye  and 
then  to  the  object,  or  first  to  the  book  and  then  to  the 
eye  ? 

3.  Hide  the  lamp  from  sight,  but  place  it  so  that  its 
light  falls  upon  the  book  ;  is  the  book  visible  ? 

4.  With   the  lamp  in  the  same  position,  hold  a  thick 
piece  of  paper  between  the  eyes  and  the  book  ;  is  it  still 
visible  ? 

5.  What  two  things  are  necessary  to  enable  us  to  see 
the  book  ? 

6.  Why  is  it  that  we  can  see  a  lighted  lamp  when  it  is 
brought  into  a  dark  room,  but  cannot  see  a  book,  chair, 
etc.  ?     The  lamp  is  said  to  be  luminous  and  the  book  is 
non-luminous. 

7.  Give  all  the  examples  you  can  of  each  kind  of  body. 
£.  How    can    you    make   a    non-luminous    body   be- 


276  NATURE    STUDY.  [March 

come  luminous  ?     How  can  you   make  it  non-luminous 
again  ? 

9.  Heat  a  wire  red-hot  in  a  darkened  room,  using  your 
alcohol  lamp  ;  can  you  see  it  from  all  sides?     Why  ? 

10.  Take  three  pieces  of  cardboard  six  inches  square. 
Place  one  on  top  of  the  other  and  cut  a  very  small  hole 
through  all  of  them  ;  place  these  upright  several  inches 
apart.     Opposite  the  hole  in  one  of  the  cardboards  place 
a  lighted  candle  ;  can  you  so  place  the  other  two  pieces 
that  the  light  will  shine  through  the  holes  in  all  three  ? 
If  so,  what  do  you  notice  about  the  three  holes  with 
respect  to  each  other  ? 

11.  Why  is  it  the  light  will  shine  through  all  three 
only  when  they  are  in  a  certain  position  ? 

12.  Arrange  a  lamp  and  book  as  in  (3)  and  try  to  see 
the   book   by  looking   through  the  holes  in  the  three 
cards  ;    what  do  you  notice  about  the  position  of   the 
holes  when  the  book  becomes  visible  ?     What  do  these 
experiments  show  you  about  the  lines  or  rays  of  light  ? 

13.  Where   does  the    light   come  from  in   (3)   which 
makes  the  book  visible  ?     Describe  the  path  it  must  take 
from  the  lamp  to  the  eye.     In  the  same  way,  in  daylight, 
describe  the  paths  of  the  rays  of  light  which  make  the 
different  objects  about  you  visible. 

14.  Instead   of  the  book   used   in   (3),  place  a  small 
looking-glass,  and,  if  a  sunbeam  can  be  substituted  for 
the  lamp,  it  will  be   better.      What  difference  do  you 
notice  in  the  visibility  of  the  two  objects  ? 

15.  Can  you  see  both  the  book  and  the  glass  equally 
well  from  all  positions  ? 

16.  Explain  why  there  is  a  difference  in  the  visibility 
of  the  two  objects.     What  difference  do  you  notice  in 
their  surfaces  ? 


March]  PHYSICS.  277 

17.  The  light  from  the  book  is  said  to  be  irregularly 
reflected  or  diffused  light,  and  that  from  the  looking-glass 
is  regularly  reflected.  Compare  the  relation  of  the  rays 
to  each  other  as  they  approach  the  surface  of  the  book 
and  the  surface  of  the  mirror  with  their  relation  to  each 
other  as  they  leave  these  surfaces.  By  which  kind  of 
light  do  you  see  most  of  the  objects  about  you  ?  What 
is  essential  to  a  good  reflector  ?  Good  reflectors  are 
called  mirrors.  A  mirror  with  a  flat  surface  is  called  a 
plane  mirror. 

18.  When  rays  of  light  strike  a  mirror,  what  happens 
to  them  ?     The  rays  from  the  object  to  the  mirror  are 
called  incident  rays,  and  those  from  the  mirror  are  called 
reflected  rays. 

19.  Conceal  the  book  as  in  (3)  from  the  eye,  but  place 
it  so  that  rays  of  light  will  pass  from  it  to  a  mirror  : 
can  you  so  place  yourself  with  respect  to  the  mirror  that 
the  figure  of  the  book  will  appear  ?     Do  you  really  see 
the  book  ?     How  can  you  prove  that  you  do  or  do  not 
see  it  ? 

20.  Explain  how  the  mirror  brings  the  appearance  of  the 
book   into  view.     To  do  this,  recall  (3),  (4),  and  (5)  re- 
lating to  the  visibility  of  an  object.     When  is  the  object 
itself  visible  ?     The  appearance  of  an  object  as  seen  in  a 
mirror  is  called  its  image. 

21.  Which  rays  determine  the  direction  in  which  the 
image  is  seen,  the  incident,  or  reflected  rays  ? 

22.  Allow  a  small  beam  of  light  to  fall  upon  a  mirror 
and  be  reflected  ;  make  the  beam  more  distinctly  visible 
by   striking  two    black-board    erasers   together  near  it. 
Erect  a  perpendicular  line,  called  a  normal,  to  the  sur- 
face of  the  mirror  at  the  point  of  reflection  ;  note  the  two 
angles  thus  formed.     The  one  between  the  normal  and 
the  incident  beam   is   the   angle   of  incidence ;  between 


278  NATURE    STUDY.  [March 

normal   and   the   reflected   beam,  the   angle  of  reflection 
Compare  these  two  angles. 

23.  Support  horizontally  a  light  straight  stick  about 
two  feet  long  on  its  ends  eight  or  ten   inches  from  the 
floor  or  table.     From  its  middle  point  suspend  a  plumb 
line.     A  bullet  partly  split  and  then  closed  upon  a  small 
thread  will  do  for  this.     Fill  a  goblet  or  pan  with  water 
blackened  with  ink,  and  place  it  under  the  line  so  that  the 
weight  will  be  below  its  surface.     In  the  side  and  near 
one  end   of  the  stick,  drive  a  tack  or   small    nail,  and 
standing  at  the  other  end,  place  the  eye  in  such  a  position 
that  its  image  will  appear  where  the  string  touches  the 
water.     Compare  the  distance  the  eye  is  from  the  point 
where  the  plumb  line  is  attached  to  the  stick  with  the  dis- 
tance the  tack  is  from  it.     Make  a  drawing  of  the  ap- 
paratus, showing  by  a  line  the  course  of  the  incident  ray 
from  the  tack,  and  the  reflected  ray  to  the  eye.     Point 
out  the  angles  of  incidence  and  reflection.     What  does 
this  experiment  show  as  to  their  relative  size  ? 

24.  Can  you  see  any  reason  why  an  image  should  appear 
to  be  behind  the  mirror  ?     Can  you  by  drawing  a  figure 
representing  a   mirror,  an  object,   its   image,  and    lines 
representing  the  rays  of  light,  show  how  far  behind  the 
mirror  the  image  must  appear  ? 

25.  Is  the  image  seen  by  means  of  the  mirror  a  real 
one,  /.  e.,  does  it  really  exist  behind  the  mirror  ?     Such 
an  image  is  called  a  virtual  image. 

26.  Hold  a  printed  page  before  a  mirror  ;  explain  why 
the  letters  appear  changed. 

27.  Can   you    explain    why  a  surface    which    diffuses 
light  does  not  give  us  images  of  objects  ? 

28.  Allow  a  beam  of  light  to  strike  a  concave  mirror  ; 
what  peculiarity  do  you  notice  about  the  reflected  rays  ? 


March]  PHYSICS.  279 

Explain  why  they  form  a  cone  of  light,  by  using  what  was 
learned  in  (22)  and  (23).  The  point  at  which  the  rays 
meet  is  called  the  principal  focus  of  the  mirror.  Meas- 
ure its  distance  from  the  middle  point  of  the  mirror. 
The  middle  point  of  the  mirror  is  called  the  center  of  the 
mirror. 

29.  In  constructing  a  normal  (see  22)  to  the  surface, 
notice  its  relation  to  the  sphere  of  which  the  mirror  forms 
a  part.     Where  in  the  sphere  do  all  the  normals  meet  ? 
This   point   is   called    the  center   of  curvature.     A    line 
drawn  through  the  center  of  curvature  to  the  center  of 
the  mirror  is  the  principal  axis  ;  all  other  lines  through 
the  center  of  curvature  to  the  mirror  are  secondary  axes. 

30.  Darken  the  room  and  hold  a  small  lighted  candle 
close  to  a  concave  mirror  ;  what  are  the  points  of  differ- 
ence between  its  image  here  and  the  one  it  forms  in  a 
plane  mirror  ?     In  what  respects   are   the   two   images 
alike  ? 

31.  Move  the  candle  back  from  the  mirror  until  it  is 
between  the  principal  focus  and  the  center  of  curvature. 
Hold  a  sheet  of  paper,  for  a  screen,  back  of  the  candle  ; 
carefully  compare  the  image  here  produced  with  the  one 
seen  in  (30). 

32.  Make  a  diagram    of  the  mirror  and  the  candle. 
Draw  two  or  more  lines,  representing  rays  of  light,  from 
the  tip  of  the  flame  to  the  mirror  ;  show  what  will  be- 
come of  those   rays  when  reflected.     Recall   what  was 
learned  in  (23).     At  what  place  in  the  reflected  rays  do 
you  find  the  image  ?     This  point  is  called  the  conjugate 
focus. 

33.  The  image  formed  in  (32)  is  called  a  real  image  ; 
how  does  it  differ  from  a  virtual  image  ?     See  (25). 

34.  Move  the  candle  away  from  the  mirror  ;  what  be- 


280  NATURE   STUDY.  [March 

comes  of  the  image  on  the  screen  ?  As  the  candle  is 
farther  removed,  where  does  the  image  next  appear  ?  Is 
it  a  real  or  a  virtual  image  ? 

35.  Again  diagram,  as  in  (32),  and  find  where  the  re- 
flected rays  from  the  candle  meet  ;  at  what  place  along 
the  reflected  rays  do  you  find  the  image?      Explain  why 
the  image  is  inverted  here,  and  why  upright  in  (30). 

36.  Notice  where  the  candle  is,    with  respect  to  the 
center  of  curvature  and  principal  focus,  when  the  image 
appears  on  opposite  sides  of  it ;    that  is,  between  the 
candle  and  mirror,  and  beyond  the  candle.     Try  to  ex- 
plain why   you   can   see  a  real  image  in   either   place. 
Recall  what  was  learned  in  (3),  (4),  and  (5).     Do  not 
confuse  what  is  necessary  to  see  an  image  with  what  is 
necessary  to  form  one. 

37.  Show  by  a  diagram  why  the  size  of  the  image 
varies  with  the  position  of  the  object. 

38.  Hold  the  candle  before  the  convex  surface  of  the 
reflector  ;  in  what  respects  is  the  image  the  same  as  that 
formed  by  a  plane  mirror  ?     In  what  respects  is  it  dif- 
ferent ? 

39.  Explain  the  formation  of  the  image  in  the  convex 
mirror  by  diagrams,  keeping  constantly  in  mind  the  laws 
by  which  those  formed  by  plane  and  concave  mirrors 
were  explained. 

40.  It  will  be  interesting  to  illustrate  how  light  varies 
in  intensity  with  the  distance  from  its  source.     Make 
from  cardboard  three  screens,  one  six  inches  square, 
one   a   foot   square,  -and   one    eighteen    inches   square 
Draw  lines  across  the  last  two,  dividing  them  into  areas 
each  six  inches  square.     Fasten  each  screen  in  an  upright 
a  few  inches  in  height.     This  may  be  made  by  splitting  a 


March]  PHYSICS.  281 

stick,  into  which  the  card  may  be  slipped  and  fastened 
with  a  tack.     A  small  block  will  answer  for  a  base. 

41.  Place  the  smallest  card  three  feet  from  the  flame  ; 
how  far  from  the  flame  must  the  second  in  size  be  placed 
to  be  exactly  covered  by  the  shadow  of  the  first?    At 
what  distance  from  the  flame  must  the  largest  be  placed 
to  be  exactly  covered  by  the  shadow  of  the  second  ? 

42.  With  the  three  cards  in  these  positions,  what  do 
you  notice  as  to  the  amount  of  light  that  each  would  re- 
ceive from  the  flame  ?     How  much  would  each  six-inch 
square  on  the  second  and  third  screen  receive,  as  com- 
pared with  that  received  by  the  smallest  card  ? 

43.  How  would  the  intensity  vary  at  the  points  occu- 
pied by  the  second  and  third  cards,  as  compared  with 
that  occupied  by  the  first  ? 

44.  Does  the  edge  of  the  card  make  a  clear-cut  shadow 
at  its  margin  ?     Hold   a  pencil  between  a  light  and  a 
screen  ;  how  does  the  edge  of  the  shadow  change  as  it  is 
moved  toward  or  away  from  the  screen  ? 

45.  If   possible,   use  a   flat    flame,  and   examine   the 
shadows  cast  by  the  edges  and  by  its  flat  surface.     Make 
a  diagram,  drawing  lines  from  the  different  parts  of  the 
flame  to  different  parts  of  the  object,  and  to  the  shadow 
beyond  ;  can  you  account  for  the  peculiarities  noticed  in 
the  shadow  ? 

46.  The  dark  central  part  of  the  shadow  is  called  the 
umbra  ;  the  light  border  is  called  the  penumbra. 

47.  Can  you  explain  the  difference  that  may  be  noticed 
between  the  shadow  of  an  object  cast  in  the  moonlight  and 
that  from  one  illuminated  by  electric  light  ? 

REFERENCE.     Humboldt  Library  :  No  37,  Six  Lectures  on  Light. 


Cbemietr?, 


NITROGEN. 

Nitrogen  is  less  interesting  than  any  of  the  gases  that 
have  been  examined.  On  account  of  its  abundance  in 
the  atmosphere  and  the  important  function  it  performs, 
however,  it  is  thought  best  to  make  some  study  of  it. 
The  pupils  should  very  early  be  taught  about  the  con- 
stituents of  air,  and  should  know  the  chief  properties  of 
each  ;  also,  as  far  as  possible,  by  simple  experiment,  they 
should  be  taught  about  the  origin,  the  cause  of  variation, 
and  the  effects  of  each  upon  themselves  and  other  living 
things. 

1.  Nitrogen  may  be  made  in  several  ways,  none  of  which 
are  very  suitable  to  be  performed  by  young  children.     Two 
methods  will  be  given,  which  are  perfectly  safe  and  pre- 
sent but  few  difficulties.     The  most  instructive  way  is  as 
follows  :  Take  a  piece  of  phosphorus  half  the  size  of  a 
pea,  and  dry  it  with  blotting  paper.     Place  it  in  a  small 
cup  or  upon   a  bit  of  porcelain,  which  may  be  floated 
upon  a  small  block  of  wood  in  a  pan  of  water.     Ignite  it, 
and   immediately  place  over  it  an  empty  glass  fruit  jar. 
When  the  burning  has  ceased,  allow  the  white  fumes  to 
clear  away,  and  then  invert  the  vessel,  without  allowing 
the  water  to  escape,  as  directed  in  the  experiments  with 
oxygen. 

2.  The  second  method  is  to  take  two  parts  of  bichro- 

282 


March]  CHEMISTR  Y.  283 

mate  of  potash  (about  one  ounce)  and  ammonium  chlo- 
ride one  part.  Grind  the  two  together  until  fine  and 
well  mixed.  Heat  in  a  flask  arranged  as  directed  in  the 
experiment  with  oxygen,  and  collect  in  a  jar  over  water. 
By  the  latter  method  the  gas  may  be  generated  in  a  flask, 
and  a  test-tube  full  may  be  caught  by  each  pupil  as  it 
forms.  The  cost  of  the  material  in  either  case  need  not 
be  more  than  fifteen  or  twenty  cents,  to  supply  fifty 
pupils  with  two  or  three  test-tubes  of  the  gas. 

3.  Why  does  the  phosphorus  continue  to  burn  after  the 
jar  has  been  inverted  over  it  in  (i)  ? 

4.  What  does  the  rising  of  the  water  in  the  vessel,  as 
the  burning  ceases,  indicate  ? 

5.  Light  a  long  splinter  and  thrust  it  into  the  jar  of 
gas  ;  each  pupil  may  do  this  with  his  test-tube.     The  gas 
may  be  kept  until  wanted  by  holding  the  thumb  over  its 
mouth. 

6.  What  is  the  effect  upon  the  blaze  ?     What  other  gas 
with  which  you  have  experimented  has  the  same  effect? 

7.  Into  another  and   perfectly  clean  test-tube  full   of 
the  gas,  pour  a  little  lime-water  ;  does  it  undergo  any 
change  ?     What  gas  causes  lime-water  to  become  milky  ? 

8.  The  gas  formed  in  the  above  experiments  is  nitro- 
gen ;    compare   it  with  the  other  gases  that  you  have 
made  in  previous  experiments. 

9.  When  the   phosphorus  burned  in  the  air  in  the  jar, 
the  oxygen  combined  with  it  and  phosphoric  acid  was 
formed,  which  was  then  dissolved  in  the  water,  leaving 
the  nitrogen  in  the  jar  ;  why  could  we  not  get  pure  nitro- 
gen by  burning  a  candle  in  the  jar  instead  of  phosphorus  ? 

10.  Note  the  amount  of  water  in  the  jar  after  the  phos- 
phorus stopped  burning  ;  how  does  it  compare  in  bulk 
with  the  gas  above  it  ? 


284  NATURE   STUDY.  [March 

11.  What  gas  did  the  water,  in  rising,  take  the  place 
of? 

12.  The  air  is  a  mixture  consisting  of  one-fifth  oxygen 
and  four-fifths  nitrogen  ;  what  would   happen  if  it  were 
pure  oxygen  ?     If  it  were  pure  nitrogen  ?     Recall  the  ex- 
periments with  oxygen  ? 

^  The   Atmosphere. 

13.  Take  a  tumbler  partly  filled  with  lime-water  and 
expose  it  to  the  air  of  the  room  for  an  hour  or  two  ;  can 
you  see  any  change  ?     What  else  is  proven  thus  to  be  in 
the  air? 

14.  Fill  part  full  a  wide-mouthed  bottle  with  air  taken 
from  near  the  floor  of  the  school-room,  and  add  half  an 
inch  of  lime-water  ;  shake  the  water  well  in  the  bottle. 
Repeat  the  experiment,   taking  the   air  from  near  the 
point  of  influx  ;  does  the  lime-water  indicate  the  presence 
of  C02  ? 

15.  In  the   same  way  test  a  bottle  of  air  taken  from 
different  points   near  the  ceiling.     (How  can  you  get  a 
bottle  of  air  from  any  point  in  the  room  ?) 

16.  Is  the  CO2  more  abundant  in  one  place  than  an- 
other ?     Why  is  it  ?     Test  a  bottle  of  air  taken  from  out 
doors. 

17.  What   is  the  fruitful   source  of  COa  in  a  school- 
room ? 

18.  Fill  a  small  vessel  with  snow  and  salt,  and  watch 
the  outside  surface  of  the  vessel  closely  ;  what  does  this 
experiment  prove  to  be  in  the  atmosphere  besides  the 
gases  already  shown  to  be  there  ? 

19.  Place  a  small  amount  of  chloride  of  lime  in  a  dish, 
and   let   it   stand    a   short   time  ;    can   you    notice   any 
change  ?     Explain. 


March]  CHEMISTRY.  285 

20.  Look  at  a  sunbeam  as  it  streams  into  the  room  ; 
what  does  it  prove  the  presence  of  in  the  air  ? 

21.  What  contrivance   do  animals   have  for  straining 
the  solid  particles  from  the  air  before  it  enters  the  lung  ? 
(See  Respiration  for  April.) 


flDeteorolog\>, 

March  is  the  fickle  month  of  the  year,  and  the  ap- 
proach is  usually  awaited  with  feelings  of  mingled  hope 
and  dread.  To  most  people,  all  semblance,  even,  of 
natural  law  appears  to  be  wanting  in  the  spiteful  play 
of  the  elements  that  are  apparently  uncontrolled.  In 
the  gales  that  generally  blow,  now  from  one  direction, 
now  from  another,  in  the  wintry  days  that  are  sometimes 
slipped  in  between  those  having  the  genuine  touch  of 
spring,  and  in  the  cautiously  swelling  buds  that  often 
come  forth  only  to  be  nipped  by  the  last  lagging  frosts, 
there  is,  indeed,  good  ground  for  the  reputation  that 
the  month  sustains.  It  will  be  no  less  instructive,  how- 
ever, to  try  to  trace  the  sudden  changes  of  this  month  to 
their  causes,  than  it  is  in  those  months  of  more  steady 
meteorological  behavior. 

1.  In  which   one   of  the  preceding   months   was   the 
temperature  nearest  that  of  the  present  one  ? 

2.  Compare  the  causes  that  combine  in  each  month  to 
produce  the  temperature  noticed.     In  what  way  are  the 
causes  different  ? 

3.  In  what  respect  are  the  causes  which  operate  now 
the  same  as  those  present  in  September  ? 

4.  What  influences  give  to  March  and  September  their 
different  character  ? 

5.  Compare  the   two   months  as  to   temperature;   is 
there  any  correspondence  in  the  average  temperature  or 
in  the  rate  of  change  ? 

286  • 


March]  METEOROLOGY.  287 

6.  Compare   the   rate  of  variation   with  that  of  each 
month   since  the  lowest   temperature   of  the   year  was 
reached  ;  is  the  rate  increasing  or  diminishing  ? 

7.  Make  a  similar  comparison  with  the  months  preced- 
ing the  date  of  the  lowest  temperature  ;   how  does  the 
rate  during  that  period  compare  with    the  rate  which 
follows  the  minimum  point  ? 

8.  Compare   the  barometric  record  with  that  of  Sep- 
tember ;  what  is  the  mean  height  and  the  greatest  range 
of  movement  in  each  month  ? 

9.  Compare,  in   the  same   way,   with  the   record    for 
December ;    with    which    month    does    it   most    nearly 
correspond  ? 

10.  Can  you,  from  your  record,  determine,  whether  or 
not  the  height  of  the  barometric  column  is  affected  by 
cold? 

11.  At  what  temperature  during  the  month  has  it  stood 
highest?     At  what  temperature,  lowest? 

12.  Can  you  find  any  relation  between  the  character  of 
the  weather  and  the  height  of  the  barometric  column  ? 

13.  What  is  the  prevailing  wind  this  month?     Is  it 
generally  cold  or  warm  ? 

14.  What  was  the  prevailing  wind  for  September  ?   For 
December  ? 

15.  What  wind  prevailed  when  the  temperature  was 
lowest  ?     When  it  was  highest  ? 

•  16.  What  wind  brings  a  cloudy  sky  ?     Is  it  like  the 
preceding  months  in  this  respect? 

17.  Has  the   character  .  of   the  clouds  changed  since 
December  ?     Compare  with  those  months  in  amount  of 
cloudiness. 

1 8.  Is  the  number  of  rainy  days  greater  or  less  than  in 
the  winter  months  ? 


2  88  NATURE   STUDY.  [March 

19.  From  what  directions  do  the  heaviest  rains  come  ? 

20.  Are    the    rains    followed   by   cooler    or    warmer 
weather? 

STUDY  OF  THE  WEATHER   BUREAU  MAPS. 

21.  In  what  quarter  of  the  country  have  Low  Areas 
most  frequently  appeared  ?     Compare  with    September 
and  December. 

22.  What  has  been  the  course  of  the  great  storms  dur- 
ing the  month  ?     How  does  the  path  compare  with  that 
of  previous  months  ? 

23.  Can  you  tell  what  influence  the  Great  Lakes  have 
had   upon  their  course  ?     The  mountains  ?     The    river 
valleys  ? 

24.  Where  has  there  been  the  heaviest  rainfall  ?     Com- 
pare with  September  and  December. 

25.  Is  the  amount  of  rainfall  increasing  or  decreasing, 
as  compared  with  the  winter  months  ? 

26.  What  has  been  the  lowest  temperature  recorded  ? 
Compare  with  September  and  December.    In  what  region 
was  it  recorded  in  each  case  ? 

27.  Compare  the  isotherms  that  cross  the  country  this 
month  with  those  of  September.     Is  there  any  difference 
in  general  direction  ? 

28.  What  is  the  most  northern  isotherm  this  month  ? 
In  September?     What  does  this  indicate?     In  the  same 
way  compare  the  most  southern  isotherms. 

29.  Do  the  isotherms  bend  about  the  Great  Lakes  the 
same  way  in  both  March  and  September?  Compare  with 
December. 

30.  In  the  same  way  note  the  effects  of  the  mountains 
and  coast  lines  in  the  different  months. 


Hstronomp. 

March,  the  herald  of  spring,  is  a  month  in  which 
observations  under  this  head  are  fraught  with  especial 
interest  and  profit.  The  sun,  mounting  the  meridian,  as 
shown  by  the  shortening  shadow,  and  creeping  almost 
stealthily  northward  around  the  horizon,  mere  loth  to 
close  his  eye  at  night,  more  eager  to  begin  his  labors  in 
the  morning,  seems  instinct  with  plans  for  a  season 
which,  though  ten  thousand  times  repeated,  is  ever  new. 
The  teacher  who  fails  to  seize  the  conditions  presented 
at  this  time,  loses  one  of  the  best  opportunities  of  the 
entire  year  to  broaden  and  strengthen  his  pupils'  concep- 
tion of  the  universe.  It  is  wrong  to  suppose  that  the 
formation  of  the  great  conceptions  which  are  necessary 
for  an  intelligent  appreciation  of  nature  is  a  matter  that 
maybe  postponed  till  a  definite  time,  and  then  be  gained 
at  once.  They  are  never  gained  except  through  growth, 
and,  whether  physical  or  mental,  that  implies  small  addi- 
tions through  patient  and  prolonged  observations. 

1.  Can  you  find  any  previous  month  in  which  the  noon- 
marks   correspond  to  those  recorded  during   this  one? 

2.  What  suppositions  regarding  the  movements  of  the 
earth  can  you  make  which  will  account  for  the  observed 
facts  ?     What  is  the  correct  one  ?     Give  the  proof. 

3.  When   did  the  noon  shadow  begin  its  retrograde 
or  backward  movement  ?  Has  the  rate  of  movement  been 
uniform  since  that  time  ? 

4.  In  what  previous  month  was  the  rate  of  the  advance 

289 


290  NATURE   STUDY.  [March 

movement  of  the  noon-marks  the  same  that  it  is  now 
in  the  retrograde  movement  ?  Using  a  globe,  explain 
why  it  is  so. 

5.  On  what  date  this  month  do  you  find  equality  of 
day  and  night  ?     For  how  much  of  the  earth  is  this  true? 
This  is  the  Vernal  Equinox. 

6.  How  long  since  this  was  the  case  before  ?     Count 
the    days,    using   the   almanac.     When,  between    those 
two  dates,  was  there  the  greatest  inequality  ? 

7.  How  many  complete  seasons  have  elapsed  since  the 
same  equality  was  noticed  before? 

8.  How  many  seasons  yet  remain  to  make  a  full  year  ? 
Count  the  days  ;  what  do  you  notice  about  the  relative 
length  of  the  two  parts  of  the  year  ? 

9.  What  suppositions  can  you  make  which  will  account 
for  the  observed  inequality  in  the  two  parts  of  the  year— 
that  part  including  fall  and  winter,  and  that  including 
spring   and    summer  ?     Find    out   which    supposition    is 
correct. 

10.  What  effect,  if  any,  must  this  inequality  in  the  two 
parts  of  the  year  have  upon  the  seasons  included  in  those 
parts  respectively  ? 

11.  On  the  date  when  a  day  and  night  are  equal,  this 
month,  note  on  the  horizon  the  points  of  the  rising  and 
setting  sun.     In  what  previous  month  did  they  coincide 
with  those  of  the  present  ? 

12.  How  long  has  it  been  since  the  sun  rose  and  set  in 
the  same  place  that  it  does  now  ?     Explain  the  facts.     If 
necessary,  illustrate  with  a  globe.     How  far  has  the  sun 
moved  along  the  horizon  since  the  shortest  day  of  the 
year  ?     Since  a  day  and  night  were  equal  before  ?  Using 
a  globe,  explain. 

13.  When  day  and  night  are  equal,  measure  the  angle 


March]  ASTRONOMY.  291 

that  the  sun's  rays  make  with  the  earth  ;  can  you  deter- 
mine, from  what  you  observe,  your  latitude  ? 

14.  Can    you    by    the    same    means    determine   your 
latitude  on  December  20  ? 

15.  What  fact  would  it  be  necessary  for  you  to  know 
in  order  to  determine  your  latitude  in  the  same  manner 
on  any  day  of  the  year  ? 

16.  In  what  latitude  is  the  day  longest  in  this  month  ? 
Where   are    they    increasing    in    length     most   rapidly  ? 
Explain  this.     (See  April  Astronomy  for  remarks  on  the 
use  of  symbols.) 

17.  For  whom  does  the  sun  rise  for  the  first  time  in 
some   months,   about  the   middle   of  this  month  ?     For 
whom  does  it  set  ? 

18.  It  will  be  noticed  that  Jupiter  has  changed  from  an 
evening  to  a  morning  star  within  the  last  month  ;  explain 
how  the  change  has  been   made.     (See   Astronomy  for 
September  for  the  relative  distances  of  the  planets  from 
the  sun.) 

19.  The  period  of  revolution  of  Jupiter  is  twelve  of 
our  years,  lacking  fifty  days.     Its  time  of  rotation  is  four 
and  a  half  minutes  short  of  ten  hours.     Its  mean  diameter 
is  eighty-five  thousand  miles,  but  there  is  a  difference  of 
five  thousand    miles   between    its  equatorial    and   polar 
diameters.     Its  volume   is  over  thirteen  hundred  times 
that  of  the  earth,  but  it  weighs  only  three  hundred  times 
as    much.     Its    mean    distance     from    the    sun    is   four 
hundred  and  eighty  millions  of  miles. 

20.  Make  as  large  a  circle  as  possible,  on  the  blackboard, 
to  represent  Jupiter's  orbit,  and  another  to  represent  that 
of  the  earth  ;  and  upon  the  latter  locate  the  earth  at  the 
point  where  it  is  to  be  found  this  month  ;  in  what  position 
must  Jupiter  be  to  appear  as  morning  star  ? 


292  NATURE   STUDY.  [March 

21.  How  long  will  it  continue  as  morning  star? 

22.  When  a  planet  is  seen  in  the  same  direction  as  the 
sun,  or,  in  passing  by  it,  approaches  nearest  to  it,  it  is 
said  to  be  in  conjunction  with  the  sun.     It  is  inferior  con- 
junction^ if  the  planet  lies  between  the  earth  and  sun, 

superior  conjunction  if  the  planet  lies  on  the  opposite  side 
of  the  sun  from  the  earth.  When  a  planet  is  on  the 
opposite  side  of  us  from  the  sun,  that  is  180°  from 
superior  conjunction,  it  is  in  opposition. 

23.  In  what  positions   will   the  earth  and  Jupiter  be 
farthest   apart  ?     When    will  they  be  closest   together  ? 
What  will  be  the  distance  between  the  planets  in  each 
case  ? 

24.  Does  Jupiter  present  to  us  the  same  phases  that 
are  shown  by  Venus  and  our  moon? 

25.  Constellations  same  as  preceding  month. 

REFERENCE.    Humboldt  Library  :   No.  20,  Romance  of  Astronomy. 


EURO-ASIA.    CLIMATE. 

By  consulting  good  physical  maps,  it  will  be  found  that 
the  climatic  conditions  of  Euro-Asia  are  vastly  different 
from  those  presented  by  the  Americas  in  corresponding 
latitudes,  and  that  there  are  also  marked  contrasts  in  the 
same  latitude  in  its  own  wide  extent.  The  study  should 
be  supplemented  by  sand  modeling  as  before,  but  the 
same  precautions  necessary  in  the  use  of  devices  in  other 
subjects  apply  with  equal  force  here.  (See  Astronomy 
for  April.) 

1.  What  is  the   general   direction  of    the   great  air- 
currents  over  the  northern  part  of  Euro- Asia?     Compare 
their  direction  on  the  eastern  and  western  coasts  ;  can 
you  account  for  the  variation  that  you  notice  ? 

2.  Note  the  direction  of  the  wind  south  of  the  Hima- 
laya Mountains  ;  how  does  its  character  differ  from  that 
on  the  northern  slope  ? 

3.  What  contrasts  in  climate  are  presented  between 
that  part  of  the  continent  lying  north,  and  that  part  lying 
south  of  the  great  axis? 

4.  Contrast  the  two  regions  with  those  of  the  same 
latitude  in  North  America. 

5.  In  which  of  the  two  continents  are  the  conditions 
more  favorable  for  uniformity  of  climate  ?     Why  ? 

6.  In  what  part  of  Euro-Asia  would  you  expect  the 

293 


294  NATURE   STUDY.  [March 

greatest  extremes  ?     What  conditions  are  present  to  pro- 
duce them  ?     Study  the  course  of  the  isothermal  lines. 

7.  Where  would  you  expect  the  greater  uniformity  of 
climate,  north  or  south  of  the  Himalayas?     Why? 

8.  Compare  the  temperature  of  the  eastern  and  western 
coasts  ;  can  you  see  causes  for  variation  ? 

9.  Compare  the  coasts  with  the  interior  ;   what  cause 
operates  mainly  to  produce  variation  ? 

10.  Compare  the  variations  mentioned  in  (6)  and  (7) 
with  corresponding  regions  in  the  Americas  ;  can  you  see 
reasons  for  a  difference  ? 

11.  Contrast  the  climatic  effects  of  the  Gulf  Stream 
with  the  Japan  current,  and  account  for  the  difference  in 
climatic  influence. 

12.  In  what  respect  are  the  climatic  conditions  on  the 
southern  coast  of  Euro-Asia  different  from  those  of  the 
Gulf  coast  of  North  America  ?    In  what  respect  are  they 
alike  ? 

13.  In  what  respect  do  the  conditions  differ  on  the 
Mediterranean  Sea  from  those  on  the  southern  coast  of 
Asia? 

14.  What   influences  combine  to  produce  the  heavy 
rainfall    of    southern    Asia  ?      Compare    with    southern 
Europe. 

15.  Compare  the  region  of  heaviest  rainfall  with  that 
of  North  America  ;  what  similarity  do  you  notice  in  the 
location  ?     Why  is  the  amount  less  in   the  latter  con- 
tinent ? 

16.  Contrast  the  rainfall  of  the  great  area  north  of  the 
continental  axis  with   that   south    of  it  ;    why   does  it 
diminish  toward  the  north? 

17.  Consider  the  rainfall  in  the  great  peninsulas  and 


March]  GEOGRAPHY.  295 

peninsular  projections  that  extend  south  from  the  con- 
tinent of  Euro-Asia? 

18.  Compare  Arabia  with  Hindostan  ;  can  you  account 
for  the  difference  ?     In  the  same  way  compare  the  Malay 
peninsula  with  that  of  Spain. 

19.  How  can  you  account  for  the  difference  in  rainfall 
in  the  British  Isles  and  Newfoundland  ? 

20.  Why  is  the  rainfall  north  of  the  continental  axis 
in  Europe  greater  than  that  north  of  it  in  Asia  ? 

21.  How  can  you  satisfactorily  account  for  the  desert 
regions  in  the  highlands  of  Asia  ? 

22.  What  reason   can   you   assign   for  the  desert  of 
Arabia  ? 

23.  The  monsoons  which  blow  from  May  to  October 
toward  the  southern  Asiatic  coast  from  the  southwest, 
and  from  October  to  May  in  the  opposite  direction,  /.  e , 
from  the  northeast,  are  the  important  climatic  factors  of 
this  region. 

24.  Have  you  learned  anything  in  physics  about  air 
which  will  help  you  to  explain  the  monsoons  and  their 
change  of  direction  ? 

25.  What  climatic  conditions  favor  the  largest  cities  of 
southern  Asia  ? 

26.  Are  there  any  cities  that  have  prospered  under 
adverse  climatic  conditions  ? 

27.  How  does  the  climate  of  a  country  affect  the  char- 
acter of  a  city  ? 

28.  Contrast  the  character  of  the  people  of  southern 
with  those  of  northern  Europe  ;   to  what  extent  may  the 
differences  noted  be  attributed  to  contrasts  in  climate  ? 

29.  Are   there  any  noticeable  differences  between  the 
people  that  live  in  the  mountainous  regions  and  those  of 


296  NATURE  STUDY.  [March 

low  countries  that  are  due  to  climatic  contrasts  ?     Com- 
pare those  on  the  coasts  with  those  in  the  interior. 

30.  Can  you  see  any  constant  relation  between  the  in- 
telligence and  thrift  of  a  people  and  the  climate,  in  a 
study  of  Euro-Asia? 


During  this  month  observations  on  frost  action  should 
be  continued.  The  effects  of  freezing  and  thawing  will 
be  shown  in  various  ways.  The  manifestations  of  these 
forces  are  usually  very  slight,  and  they  will  possess  interest 
and  be  instructive  only  as  the  pupil  can  be  led  to  picture 
in  his  own  mind  what  the  results  must  be  after  a  great 
lapse  of  time.  The  idea  of  time  is  one  for  which  the 
teacher  should  work  with  the  pupils  unceasingly. 

Geological  pictures  have  not  always  presented  them- 
selves to  the  student  of  nature  as  they  now  do  to  those 
who  are  imbued  with  the  more  modern  notions  as  to 
nature's  way  of  doing.  Formerly  the  pictures  were  filled 
with  catastrophic  action,  which  annihilated  the  old,  and  as 
suddenly  established  a  new  order  of  things.  Then  came 
a  long  time  of  absolute  rest,  or  at  least  a  period  of  trifling 
change.  Now,  one  sees  in  the  picture  constant  unrest, 
it  is  true,  but  modification  so  slight  and  so  gradual,  that 
nothing  is  destroyed  except  those  things  that,  apparently 
through  a  loss  of  plasticity,  fail  to  keep  pace  with  the 
incessant  change. 

Thus  far  we  have  examined  what  may  be  considered 
some  of  the  mechanical  agencies  which  are  at  work  mold- 
ing and  changing  the  face  of  the  globe.  There  are 
others  equally  potent  and  certainly  of  no  less  interest, 
though  they  are  not  matters  of  such  common  observa- 
tion. The  agencies  now  meant  are  those  called  organic, 
and  to  gain  some  conception  of  these  we  will  include  in 

297 


298  NATURE  STUDY.  [March 

our  study  for  this  month  a  piece  of  coral.  In  many 
places,  pieces  of  coral  may  be  found  in  the  common 
stones  that  are  abundant — limestones.  When  they  cannot 
be  so  obtained,  it  often  happens  that  some  of  the  pupils 
possess  specimens  of  their  own.  At  least,  it  will  be  com- 
paratively easy  to  secure  clam,  mussel,  oyster  or  snail 
shells,  and  these  will  give  some  idea  as  to  how  mineral 
matter  may  be  deposited  by  animals,  which  is  a  necessary 
conception.  From  this,  it  should  be  the  aim  to  have  the 
pupils  picture  for  themselves  the  history  of  the  great  beds 
of  limestone. 

1.  Put  a  small  piece  of  a  shell  of  some  kind  into  a  test- 
tube  and  add  a  little  acid.     (See  Mineralogy  for  Janu- 
ary.)    Does  this  recall  any  experiments  previously  per- 
formed ? 

2.  What  kind  of  stone  does  this  remind  you  of  ?     (See 
Mineralogy  for  January.) 

3.  Examine  an  oyster,  clam,  or  mussel  as  it  lies  on  the 
half  shell  ;  also  look  carefully  at  the  outer  surface  of  the 
shell.     Can  you  tell  how  the  animal  forms  this  shell  ? 

4.  Can  you  see  the  starting  point  of  growth  ? 

5.  Can  you  tell  whether  or  not  the  shell  grows  in  thick- 
ness ? 

6.  Can  you  find  out  from  what  part  of  the  animal  the 
material  is  secreted  which  increases  the  width  of  the 
shell  ? 

7.  Notice  the  thin  membrane  that  lies  closely  against 
the  inner  surface  of  the  shell  ;  this  is  the  mantle  of  the 
animal. 

8.  Examine  a  piece  of  coral ;  what  kind  of  a  substance 
does  it  appear  to  be  ? 

9.  In  what  respects  does  it  differ  from  most  kinds  of 
stone  ? 


March]  GEOGRAPHY.  299 

10.  Use  the  acid  test  ;  what  stones  that  you  have  ex- 
amined before  does  it  resemble  ? 

11.  If  you  have  a  specimen  of  the  branching  coral,  ex- 
amine the  curious  little  rosette  like  pits  along  the  sides  ; 
what  similarity  do  you  find  among  them  ? 

12.  These  little  pits  were  once  occupied  by  small  jelly- 
like  animals  (not  insects,  as  we   frequently  hear  them 
named)  called  coral  polyps.     As  they  grew,  they  secreted 
the  stony  substance,  not  as  the  oyster  does,  in  a  covering, 
but  in  the  lower  part  of  the  body.     These  minute  animals 
can  live  only  in   the  warm,  clear  waters  of  the   tropical 
seas,  and   at  a  depth  not  exceeding  one   hundred  and 
twenty  feet.     They  are  so  small  and  delicate  that  one 
would  almost  at  first  think  that  they  would  have  to  live 
in  the  quiet  places  of  old  ocean,  but  the  reverse  is  the 
case.     Can  you  see  why  the  dashing  waves  and  the  sweep 
of  great  ocean  currents  are  necessary  for  their  existence  ? 
You  can  scarcely  make  a  mistake  in  the  answer.     The 
myriads  of  these  little  polyps  which  live  together,  in  the 
course  of  time  build  up  great  masses  of  stone.      The 
waves  break  off  the  branches,  which  settle  to  the  bottom, 
and  in  this  way  a  solid  wall  is  formed.     These  are  often 
built  out  a  little  distance  from  an  island,  and  coming  to 
the  surface  form  coral  reefs.     These  great  rock  walls  are 
sometimes  thousands  of  feet  deep  ;  what  reasonable  sup- 
position can  you  make  which  will  account  for  this,  since 
the  polyps  can  live  only  at  the  depth  given  above  ? 

13.  Judging  from  the  location  where  the  polyps  live, 
what  would  be  the  effect  finally  upon  their  stony  struc- 
ture ? 

14.  Look  closely  at  the  texture  of  the  strong  coral  ;  if 
it  were  to  be  worn  away  by  the  water,  would  it  likely 
make  a  fine  or  a  coarse  material  ? 


3°°  NATURE  STUDY.  [March 

15.  What  would  become  of  the  material  thus  worn  off, 
as  well  as  that  which  would  be  derived  from  the  shells  of 
dead  animals  such  as  the  clam  and  oyster  ? 

16.  Would  this  material  retain  any  of  the  form  of  the 
original  shells  or  corals  ? 

17.  What  property  of  the  original  shell  or  coral  would 
still  be  retained  by  the  material  worn  away  ? 

18.  In  the  examination  of  any  of  the  stones  that  you 
have  seen,  have  you  found  any  fragments  of  corals  or 
shells  ? 

19.  What  would  such  fragments  indicate  as  to  the  ori- 
gin of  the  stones  ? 

20.  In  what  kind  of  stones  were  such  fossils  found  ? 
What  does  that  tell  as  to  their  history? 

REFERENCE.     Humboldt  Library:   No.  6,  Town  Geology;    No. 
no  Story  of  Creation. 


It  will  be  useful  at  this  time  to  begin  a  little  closer 
study  of  the  minerals  that  may  have  been  collected  dur- 
ing the  year.  The%  may  be  readily  sorted  and  classified 
by  very  small  pupils  with  respect  to  their  structure,  which 
in  many  cases  is  quite  obvious  to  the  naked  eye.  The 
external  form  of  most  of  the  minerals  in  their  collections 
has,  no  doubt,  been  determined  by  forces  which  have 
had  nothing  to  do  with  forming  the  mineral  originally. 
That  is,  they  are  probably  fragmentary  and  angular,  or 
rounded  as  the  water-worn  pebbles.  Here  the  external 
form  is  of  no  use  in  the  description  of  the  mineral. 
Sometimes,  a  few  may  be  found  whose  form  is  not  due  to 
such  causes,  and  attention  should  be  given  to  them 
as  they  occur. 

1.  Look  among  your  collection  for  stones  that  are  seen 
to  be  hollow  ;    sometimes  they  are   rounded  pebbles  so 
worn  away  as  to  expose  the  hollow  within.     Such  a  stone 
is  called  a  geode. 

2.  Note  the  inner  surface  of  the  geode  ;  is  it  covered 
with  crystals  or  is  it  smooth  ?     Sometimes  its  inner  sur- 
face is  covered  with  a  layer  full  of  rounded  protuberances. 
This  form  of  mineral  is  said  to  be  botryoidal. 

3.  Have  you  any  stones  in  your  collection  which  were 
formed  in  rounded  masses  ?     An  examination  of  the  sur- 
face will  usually  show  at  once  whether  they  are  water- 
worn  or  not.     Such  stones  are  called  concretions,  and  are 
said  to  be  concretionary. 


302  NATURE  STUDY.  [March 

4.  Have  you  any  specimens  in  which  the  material   is 
arranged   in    layers,    as   in  slate  ?     This  is  said   to   be 
stratified. 

5.  Sometimes  about  springs  of  certain  kinds  the  water 
deposits  a  porous  incrustation  of  rock.     It  is  very  light, 
and  often  sponge-like  in  appearance,  and  is  called  tufa. 
It  is  said  to  be  tufaceous. 

6.  In  caves,  sometimes  the  water  which  drips  from  the 
roof  leaves  hanging  an  icicle-like  mineral  deposit  which 
is  called  a  stalactite.     The  rock  is  described  as  stalactitic. 
The  water  dripping  to  the  floor  there  heaps  up  a  mound- 
like  rock  which   is  called  a  stalagmite.      Such  a  rock  is 
stalagmitic. 

7.  Can  you  find  in  your  collection  any  distinct  crystals  ? 
Are  they  perfect  ?     How  many  faces  have  they  ? 

8.  Examine  some  specimen  that  clearly  shows  a  gran- 
ular structure,  and  by  carefully  tapping  it  separate  some 
of  the  grains.     Are  they  crystals  ?     Are  there  any  per- 
fect  crystals    among    them  ?      Such    minerals   may    be 
described  as  coarsely  or  finely  granular,  according  to  the 
size  of  the  grains. 

9.  When  the  grains  are  too  small  to  be  detected  by 
the  naked  eye,  the  mineral  is  compact. 

10.  Procure  a  piece  of  mica  ;  it  is  sometimes  used  in 
stove-doors.     What  is  the  peculiarity  of  structure  ?     It 
is  foliated. 

11.  If    possible,  procure    a  small  piece  of  asbestos  ; 
such  a  mineral  \sfibrous. 


Zoology 

During  this  month,  usually,  great  abundance  of  ma- 
terial for  outdoor  study  appears.  The  calendar  started 
in  the  previous  month  will  rapidly  fill  up,  and  as  the 
days  go  by  will  prove  to  be  an  interesting  and  instruc- 
tive record.  Collections  of  every  kind  should  be  en- 
couraged, and  informal  talks  and  discussions  should  be 
permitted  as  often  as  time  and  the  disposition  of  the 
pupils  will  warrant. 

GENERAL  OBSERVATIONS. 

1.  Watch   for   the   first   appearance   of   earthworms  ; 
why  are  they  so  abundant  after  a  rain  ?     Do  they  come 
down  in  the  rain  ? 

2.  Let  the  pupils  each  select  and  measure  off  a  square 
yard  of  ground  in  different  locations  and  count  the  num- 
ber of  entrances  to  burrows  that  are  found.     What  is  the 
average  ? 

3.  In  what  locations  are  they  most  numerous  ?    Where 
are  they  fewest  ? 

4.  What  is  the  meaning  of  the  small  heaps  of  earth  at 
the  entrance  of  a  burrow  ? 

5.  How  do  they  bore  their  way  through  the  ground  ? 
Put  one  or  more  in  a  glass  of  damp  earth  for  a  few  days 
and  watch  it. 

6.  Carefully  clean  away  the  little  heaps  of  earth  from 
about  the  burrows  in  a  square  yard,  and  the  next  morn- 
ing gather  all  that  has  been  cast  up  during  the  night. 

303 


3°4  NATURE  STUDY.  [April 

Dry,  and  weigh  it ;  at  the  same  rate  how  much  would  be 
brought  to  the  surface  on  an  acre  in  one  night  ?  In  three 
months  ? 

7.  Do  they  bring  up  as  much  in  day-time  as  they  do 
at  night  ?     What  kind  of  weather  seems  to  suit   their 
work  the  best  ? 

8.  What  must  be  the  effect  of  their  work  upon  the 
soil  ?     How  must  it  affect  objects  lying  on  the  surface  of 
the  ground  ?      Notice   stones  and  flag  pavements  that 
have  begun  to  sink. 

9.  Follow  out  a  burrow  and  find  its  depth,  and  make  a 
diagram  of  it.     Is  there  more  than  one  worm  to  a  bur- 
row ?     The  burrow  may  be  followed  by  using  a  small 
wire  probe,  the  ground  being  dug  away  as  it  is  pushed 
carefully  into  the  hole. 

10.  Does  the  earthworm  eat?     If  so,  what  is  its  food 
and  when  does  it  feed  ?     What  are  its  enemies  ?     Does 
it  fight  or  seek  safety  in  flight  ?     Upon  what  does  it  de- 
pend as  means  for  concealment  ?     How  do  birds  find 
them  ? 

11.  Why  is  it  so  much  alike  on  all  sides?     Why  is  it 
not  exactly  alike  all  around  ? 

12.  In  what  respect  does  it  resemble  a  snake  ?     How 
does  it  differ  from  one  ?     Can  you  see  why  it  differs  ? 

13.  Why  are  its  two  ends  so  much  alike?    Are  they 
exactly  alike  ?     Why  are  they  at  all  different  ? 

14.  Compare  its  movements  with  those  of  a  snake  ; 
can  you  find  any  scales  or  legs  ? 

15.  Draw  it  gently  backward  through  the  fingers  and 
examine  its  sides  under  a  lens.     Count  the  segments  of 
the  body  ;  do  they  vary  in  different  specimens  ? 

16.  Does  the  earthworm  breathe  ?      Look  for  respira- 
tory movements  along  the  body. 


April]  ZOOLOGY.  3°5 

17.  Can  it  live  in  water  ?     Expose  a  worm  on  a  piece 
of  paper  to  the  sun  ;  is  there  any  evidence   of  distress  ? 
Can  you  tell  what  ails  it  ?     Put  it  into  a  dish  with  a  little 
water  in  it  and  expose  again  ;  does  it  seem  as  uncom- 
fortable as  before  ? 

1 8.  Examine  the  worm  in  a  good  light  with  a  lens  ; 
can  you  see  any  trace  of  a  circulation  ?     Lying  along  the 
back  is  a  pulsating  tubular  organ  which  assists  in  keep- 
ing the  circulating  fluid  in  motion.     The  true  blood  is 
not  red,  but  rather  milky  in  appearance,  and  does  not  cir- 
culate in  closed  vessels  as  in  our  own  bodies. 

19.  Can  the  earthworm  see  objects?      What  plan  can 
you  devise  which  will  fairly  test  this  ?     Does  it  distin- 
guish between  light  and  darkness  ? 

20.  Can  it  hear  ?     What  evidence  can  you  gather  on 
this  point  ? 

21.  Test  it  for  the  sense  of  touch.     Also  for  the  sense 
of  smell. 

BIRDS. 

1.  What  influences  bring  the  birds  north  in  the  spring  ? 

2.  What  do  those  that  arrive  this  month  have  to  feed 
upon  ? 

3.  Are   there   any   that    feed   entirely   while   on   the 
ground  ?     Are  there  any  that  never  feed  on  the  ground  ? 
Have  you  noticed  any  taking  food  while  in  flight  ? 

4.  Why  do  some  birds  hop  while  others  walk  or  run  ? 
Why  do  certain  birds  climb  trees  ?     Why  cannot  they  all 
do  it? 

5.  Compare  the  flying  of  different  birds  ;  what  things 
determine  the  character  of  the  flight  ?      Notice  shape  of 
body,  wings,  etc.,  and  the  proportion  of  the  different 
parts. 

6.  What  enables  a  bird  to  have  such  speed  in  flight  ? 


3°6  NATURE  STUDY.  [April 

Compare  the  line  of  flight  of  different  birds  ;  is  there  any 
uniform  difference  between  those  which  fly  great  dis- 
tances, and  those  that  fly  but  a  short  distance  at  a 
time? 

7.  Does  the  size  of  the  tail  affect  the  character  of  the 
flight  ?     Is  the  tail  used  for  any  other  purpose  than  that 
of  assisting  in  flight  ? 

8.  Are  there  any  good  flyers    that  have  very  short 
tails  ?     Is  there  any  substitute  for  the  tail  in  such  cases  ? 

9.  How  do  birds  dispose  of  their  legs  when  flying? 
Compare  those  of  widely  different  kinds. 

10.  How  do  birds  manage  to  cling  to  a  small  twig 
when  asleep  ?     Have  you  found  any  that  do  not  roost  in 
trees  ? 

n.  How  do  birds  seize  their  food?  Are  there  any 
that  use  both  claws  and  beak  ?  Are  there  any  that  use 
but  the  beak  ? 

12.  Do  you  know  of  any  birds  that  live  upon  the  flesh 
of  other  animals  ?     How  do  they  differ  from  those  that 
live  on  insects  and  seeds  ? 

13.  At  what  time  do  birds  sing  most  ?     Why  do  they 
sing  ?    Which  sings  the  more,  the  male  or  female  ? 

INSECTS. 

In  the  study  of  insects,  it  is  necessary  to  collect  them 
in  some  way  in  which  they  may  be  speedily  killed,  and 
yet  not  be  spoiled  for  examination.  This  may  be  done  with 
a  cyanide  bottle,  prepared  as  follows.  Drop  into  a  wide- 
mouthed  bottle  three  or  four  lumps  of  cyanide  of  potas- 
sium the  size  of  a  small  marble.  Pour  in  half  an  inch  of 
water  and  then  sprinkle  evenly  with  plaster  of  Paris,  until 
a  dry  cake  is  formed.  Wipe  inside  and  outside  with  a 
dry  cloth  and  close  with  a  tight  cork  or  cap.  Any  drug- 


April]  ZOOLOGY.  307 

gist  will  prepare  one  for  a  few  cents.  A  wide-mouthed 
morphia  bottle  is  a  very  convenient  size. 

Insects  dropped  into  this  bottle  will  be  quickly  killed 
and  yet  preserved  in  a  perfect  state  for  examination. 

Insects  may  be  mounted  and  preserved  thus :  slice 
ordinary  bottle  corks  into  pieces  one-fourth  of  an  inch 
thick  and  glue  them  to  the  bottom  of  a  box  or  tray.  A 
cigar-box  answers  the  purpose  very  well.  Pass  a  pin 
through  the  insect,  in  beetles  through  the  right-hand  half 
of  the  abdomen,  in  butterflies,  etc.,  through  the  center  of 
the  middle  division  of  the  body,  and  set  it  upright  in 
the  cork.  Keep  a  small  camphor  ball  in  the  box,  to  kill 
the  pests  that  attack  them. 

Some  insects,  such  as  butterflies,  etc.,  must  be  dried 
with  wings  spread  before  being  mounted  permanently  in 
a  tray.  Take  two  strips  of  smooth,  soft  wood  three 
inches  wide  and  about  two  feet  long.  Leaving  a  space 
one-fourth  inch  wide  between  them,  nail  them  side  by 
side  to  two  blocks  of  wood,  one  on  each  end.  The 
upper  surface  of  these  blocks  should  be  cut  slightly 
slanting  toward  the  middle,  so  that  the  strips  when  nailed 
on  will  be  somewhat  trough-like.  Tack  underneath  the 
space  between  the  strips  a  piece  of  soft  wood,  card-board, 
or  cork.  Pass  a  pin  through  the  body  of  the  insect,  as 
directed  above,  and  pin  it  fast  to  the  cork,  placing  its 
body  ir^  the  space  between  the  strips.  Draw  the  wings 
forward  to  the  natural  position,  and  fasten  by  pinning 
narrow  strips  of  paper  across  them. 

1.  Collect  and  sketch  the  insects  that  first  appear  ; 
when  are  they  to  be  found  ? 

2.  Are  they  young  ones,  or  have  they  lived  through 
the  winter  ? 

3.  What  is  their  food  ?     Of  what  are  they  the  prey  ? 


308  NATURE  STUDY.  [April 

4.  What  means  of  escape  and  defense  have  they  ? 

5.  When  are  they  more  frequently  abroad,  in  daytime 
or  night  ? 

6.  What  modes  of  concealment  have  they  ? 

7.  How  does  their  flight  differ  from  that  of  a  bird  ? 

8.  Do  any  insects  possess  wings  without  having  the 
power  of  flight  ? 

9.  How  does  the  number  of  wings  vary  in  different 
kinds  ?     How  are  they  used  ? 

10.  How  do  they  walk  or  run  ?     Make  a  sketch  show- 
ing the  order  in  which  they  move  their  legs. 

POND  LIFE. 

1.  Secure  a  mass  of  frogs'  eggs  from  a  pond  or  ditch 
and  place  them  in  a  jar  of  water.     Toads'  eggs  are  dis- 
tinguished by  their  being  in  long  strings. 

2.  What  are  the  earliest  signs  of  life  ?     Can  you  dis- 
cover movements  before  the  eggs  are  hatched  ? 

3.  As  soon  as  hatched,  examine  one  of  the  tadpoles 
closely  ;  how  does  it  swim  ? 

4.  Has  it  any  appendages  ?     Look  closely  about  the 
mouth  for  gills  ? 

If  a  microscope  can  be  obtained,  place  one  of  the  little 
creatures  on  a  piece  of  glass  with  a  little  water  (a  watch 
glass  is  best)  and  examine  the  gills.  The  blood  flow 
thus  revealed  is  a  thing  of  rare  beauty.  ^ 

5.  It  is    difficult    to    preserve    the  same    specimens 
through  all  the  changes,  and  new  ones  must  be  obtained 
as  needed. 

6.  What  becomes  of  the  external  gills  ?     How  do  they 
breathe?     Look  just  behind  the  mouth  for  a  small  open- 
ing ;  this  leads  to  internal  gills. 

7.  What  is  their  food  ?     Is  the  number  of  tadpoles 


April]  ZOOLOGY.  3°9 

which    develop   into    frogs   relatively   large    or   small  ? 
Why  ? 

8.  Do  you  notice  anything  different  in  the  early  life  of 
a  toad  from  that  of  a  frog  ? 

RESPIRATION. 

1.  Standing  erect,  inhale  slowly  a  full  breath.    Through 
what  openings  does  the  air  enter? 

2.  Can  you  close  the  mouth  and  inhale  through  the 
nostrils  ?    Can  you  inhale  equally  well  through  the  mouth 
alone  ? 

3.  What  muscles  of  the  trunk  seem  to  be  most  con- 
cerned in  inhaling  air?     In  exhaling? 

4.  What  changes  occur  in  the  shape  or  size  of  the  chest 
in  breathing?     With  a  string  or  tape  measure  find  out 
how  many  inches  the  chest  varies  in  size. 

5.  In  what  part  does  it  change  most? 

6.  Is  the  air  filling  the  lungs  the  cause  or  effect  of 
the  expansion  of  the  chest  ?     Close  the  mouth  and  nos- 
trils and  try  the  movements  of  inhalation. 

7.  What  experiments  in  Physics  will  explain  the  process 
of  inhalation  ? 

8.  How  do  the  ribs  move  in  inhalation  ?     In  exhala- 
tion ? 

The  chest  cavity  is  separated  from  that  of  the  abdomen 
by  a  dome-shaped  muscular  partition  called  the  dia- 
phragm. By  contraction,  the  diaphragm  is  somewhat 
flattened,  and  the  chest  cavity  is  enlarged  vertically,  thus 
assisting  in  inhalation.  When  relaxed,  the  contents  of 
the  abdomen,  which  have  been  compressed  during  its 
contraction,  force  it  back  into  its  dome  shape,  thus  assist- 
ing in  exhalation. 

9.  What  position  is  best  for  full  breathing  ? 


310  NATURE  STUDY.  [April 

10.  What  is  the  meaning  of  the  occasional  long  breath 
we  take  ?  Of  yawning  ? 

n.  Why  do  sad  thoughts  cause  us  to  sigh  ? 

12.  Do  the  common    animals,  dog,  cat,   horse,   cow, 
etc.,  breathe  through  the  mouth  or  nostrils  ? 

13.  What  advantages  in  taking  breath  through  the  nos- 
trils ? 

14.  How  do  people  who  snore  breathe,  through  the 
mouth  or  nostrils?     Open  the  mouth  and  make  full  in- 
spiration through  both  mouth  and  nostrils.    Can  you  tell 
where  the  snoring  sound  is  formed  ? 

15.  With   a  mirror  examine  the  back  of  the   mouth. 
Note  the  fleshy  flap  hanging  down  toward  the  throat. 
The  air  passes  on  both  sides  of  this  to  and  from  the 
throat  when  the  mouth  is  open,  and  causes  it  to  flutter 
more  or  less  rapidly,  thus  producing  the  peculiar  sound 
of  snoring. 

16.  Can  you  make  the  snoring  sound  with  the  mouth 
closed  ? 

17.  Count  the  number  of  respirations  to  the  minute; 
take  average  per  minute  for  five  minutes. 

18.  How  do  your  movements  affect  the    number  of 
respirations  ?     Take  the  number  after  vigorous  exercise. 

19.  How  do  the  movements  affect  the  general  charac- 
ter of  the  respirations? 

20.  In  ordinary  breathing  are  the  lungs  filled  to  their 
utmost  capacity  ?     Try  breathing  in  additional  air  after 
a  quiet  inspiration  has  ceased. 

The  extra  amount  thus  taken  into  the  lungs  is  called 
complemental  air.  That  which  passes  in  and  out  in  ordi- 
nary quiet  breathing  is  called  tidal  air. 

21.  After  an   ordinary  expiration,  can  you  still  force 
outward  an  additional  amount  ?     This  is  called  supple- 


April]  ZOOLOGY.  311 

mental,  or  reserve,  air.  After  all  has  been  forced  out  that 
is  possible,  some  air  still  remains  in  the  lungs ;  this  is 
called  residual  air, 

22.  Prepare  a  small  amount  of  lime-water  and  breathe 
into  it  through  a  tube.    Does  this  recall  any  other  exper- 
iment ? 

23.  What  was  it  that  changed  the  lime-water  in  the 
former  experiment  ? 

24.  Try  stirring  fresh  lime-water  with  a  glass  rod,  so 
as  to  mix   it   with   pure  air.      Does  it  show  the   same 
change  ? 

25.  Is  the  air,  when  it  leaves  the  lungs,  of  the  same 
composition  it  was  when  it  entered  them  ? 

26.  What  are  the  effects  you  have  noticed  upon  your- 
self when  in  a  poorly  ventilated  room  containing  several 
persons  ? 

27.  Fill  a  jar  with  water  and  invert  it  in  a  pneumatic 
trough,  as  directed   in   lessons  on  oxygen.      Take  full 
breaths  and  by  means  of  a  tube  fill  the  jar  with  air  from 
the  lungs. 

28.  Test  the  air  in  various  ways  ;  note  the  odor.     Try 
burning  a  splinter  in  it.    Can  you  tell  what  the  air  lacks  ? 
\Vhat  has  become  of  the  missing  part  ?     What  has  it 
gained  from  the  body  ? 

29.  In  what  respect  are  our  bodies  like  a  burning  stick  ? 
(See   Chemistry   for   March    and   also    previous  lessons 
in  Physics.) 

REFERENCE.  Humboldt  Library  :  No.  i,  Light  Science  for  Leisure 
Hours.  See  "  The  dust  we  have  to  breathe."  No.  92,  Formation  of 
Vegetable  Mold  by  Earthworms. 


Botany 

During  this  month  much  attention  should  be  given  to 
germination,  as  the  young  plantlets  appear.  It  is  impos- 
sible to  cast  in  any  single  outline  a  set  of  directions  which 
will  exactly  suit  the  environment  of  every  teacher. 
The  time  has  come,  however,  when  teachers  should 
cease  trying  to  follow  some  one  else  step  by  step  ; 
no  one  has  ever  risen  in  his  work  by  following,  no  matter 
how  perfect  the  leader.  An  outline,  at  best,  can  only 
furnish  a  teacher  with  hints  and  suggestions  as  to  how  he 
may  utilize  his  own  conditions.  It  adds  immensely  to 
the  vitality  of  the  work  with  the  pupils,  if  the  plants  that 
come  up  at  random  outdoors  be  used  as  specimens  for 
study.  It  is  surprising  how  small  a  spot  will  furnish  an 
abundant  supply  for  an  entire  school.  That  the  whole 
process  of  germination  may  be  observed  from  the  begin- 
ning, however,  it  is  well  to  have  seeds  planted  in  some 
manner  in  the  school-room  also.  There  are  many  devices 
that  may  be  used  successfully  for  this  purpose,  but,  on 
the  whole,  there  is  perhaps  nothing  better  than  some 
suitable  vessel  filled  with  clean  sand. 

A  pan  that  has  proved  useful  and  convenient  is  one 
made  of  galvanized  iron,  thirty  inches  long,  eight 
inches  wide  and  four  inches  deep.  By  filling  it 
two-thirds  full  of  sand,  space  enough  is  left  above 
to  admit  of  glass  being  placed  over  the  young  plants 
if  the  weather  be  very  severe ;  but  this  precaution 
is  rarely  necessary.  By  allowing  to  one  pupil  a  space 

312 


April]  BOTANY.  3*3 

of  three  inches,  such  a  pan  will  accommodate  eight 
persons,  and  there  will  be  a  six-inch  space  left  as 
common  ground  rn  which  odd  or  curious  forms  may  be 
grown,  such  as  bulbs,  underground  stems,  etc.  Five 
pans  of  this  kind  will  equip,  at  a  trifling  outlay,  an  ordi- 
nary school-room  with  a  useful  outfit  that  will  last  for 
years.  No  trouble  or  time  is  required  beyond  what  is 
necessary  to  keep  the  sand  moist  and  the  pan  near  a 
window.  The  pans  when  well  made  are  water  tight, 
without  being  soldered,  and  will  be  found  very  useful  in 
other  seasons  in  many  experiments  in  physics  and  chem- 
istry when  pneumatic  troughs  are  needed.  The  develop- 
ment of  buds  may  be  observed  by  placing  small  twigs  in 
bottles  of  water.  A  few  wide-mouthed  bottles,  such  as 
may  be  easily  procured  by  the  pupils,  will  enable  them 
to  watch  without  trouble  the  development  of  the  buds  of 
every  different  kind  of  tree  and  shrub  in  the  neighbor- 
hood. Some  of  the  twigs  start  their  buds,  when  treated 
thus,  quite  slowly  ;  others  develop  almost  at  once,  and 
not  a  few  not  only  put  forth  leaf  and  flower,  but  plenty 
of  roots  too.  The  twig  should  not  be  more  than  six 
inches  long  and  should  have  a  terminal  bud,  that  its 
functions  may  be  studied. 

GERMINATION. 

1.  Plant  some  of  the  seeds  that  were  gathered  last  fall. 
(See    September   Botany.)      With  beginners   use   large 
seeds  of  some  kind  first.     Plant   carefully,   placing  the 
seeds  in  different  positions  and  at  different  depths. 

2.  Make  the  conditions  different  for  the  same  kind  of 
seeds.     Place  some  in  the  dark,  or  cover  with  a  tin  cup 
or  flower   pot.     Plant   some  in  dry  sand.     Keep  some 
cold  and  others  warm. 


3i4  NATURE  STUDY.  [April 

3.  As  the  seeds  begin  to  grow,  write  a  list  of  what  ap- 
pear to  be  the  most  favorable  conditions  for  development. 

4.  Do  different  seeds,  under  the  same  conditions,  grow 
equally  well  ? 

5.  Where  does  the   plant  get  its  first  food  to  give  it  a 
start  before  it  has  either  leaf  or  root  outside  the  seed 
coats  ? 

6.  When  the  seed  coats  burst,  as  growth  begins,  closely 
examine  what  is  inside  ;  what  parts  of  a   plant  can  you 
recognize  ? 

7.  As  growth  proceeds,  watch  daily  what  becomes  of 
the  different  parts  of  the  seed  ;  what  parts  do  not  con- 
tinue with  the  growing  plant  ?     What  parts  develop  as 
the  plant  grows  ? 

8.  Are  the  seeds   you    find  sprouting  outdoors  near 
the  parent  plant  ?     Can   you  tell  how  they  came  to  be 
planted  where  they  are  ? 

9.  Scrape  away  the  surface  of  the  ground  from  some 
spot  and  take  up  a  box  of  earth  that  has  been  buried 
several  inches.     Put  this  in  a  suitable  place  and  watch 
for  the  sprouting  of  any  seeds  it  may  contain.     Take  up 
a  small  box  of  earth  from  the  surface  in  another  place  ; 
how  many  different  kinds  of  plants  grow  from  it? 

10.  In  some  place  not  likely  to  be  disturbed,  mark  off 
a  square  yard  of  ground  and  count  the  different  kinds  of 
plants  it  produces.     Can  you  tell  where  the  seeds  that 
sprout  in  this  space  came  from  ? 

11.  With  what  adverse   influences  do  the    sprouting 
seeds  and  young  plants  have  to  contend  ? 

12.  Look  for  plants  of  the  same  kind  in  different  loca- 
tions ;  compare  the  growth  of  those  under  trees  or  in  the 
shade  of  buildings  with  those  away  from  such  influences 
Compare  those  growing  in  sand  with  those  in  soil. 


April]  BOTANY.  3J5 

13.  Do  they  grow  alike  on  different  sides  of  a  house  ? 

14.  Compare  the  chances  of  those  that  start  early  with 
those  that  sprout  later. 

A    SEED. 

Synopsis  of  the  terms  that  may  be  used  at  the  teacher's 
discretion,  in  a  study  of  the  seed. 

I.  OUTER  PARTS. 

Hilum  or  scar  ;  the  point  where  it  was  attached 

to  the  pod. 

Micropyle  ;  minute  opening  near  the  hilum. 
Seed  coats  ;  outer,  testa  ;  inner,  tegmen. 

II.  INNER  PARTS. 

Cotyledons ;  the  thickened  leaves  in  which  nour- 
ishment is  stored.  When  there  are  two  cotyle- 
dons, the  plant  is  a  dicotyledon  ;  when  but  one, 
it  is  a  monocotyledon.  Find  examples  of  each. 

Plumule ;  small  terminal  bud  lying  between  the 
cotyledons,  or  embedded  in  it  when  there  is 
but  one. 

Caulicle  or  Radicle  ;  small  stem  within  the  seed 
coats. 

Embryo  ;  the  plantlet  within  the  seed  coats. 

DEVELOPMENT  OF  BUDS. 

1.  Which  seems  to  be  in  advance,  the  sprouting  of  the 
seeds,  or  the  unfolding  of  the  buds  ? 

2.  Which  is  the  more  serious  loss  to  a  plant,  the  de- 
struction of  a  seed,  or  the  loss  of  a  bud  ?     Which  are 
destroyed  in  greater  numbers,  seeds  or  buds  ? 

3.  Compare,  as  well  as  you  can,  the  ratio  of  the  seeds 
that  are  destroyed  to  those  that  produce  plants  with  that 
of  the  buds  that  are  destroyed  to  those  that  survive.     In 


3l6  NATURE   STUDY.  [April 

the  production  of  which  does  nature  seem  to  be  the  more 
extravagant  ? 

4.  Are  the  buds  all  equally  advanced  in  all  parts  of  the 
tree?     Compare  the  opposite  sides  and  the  top  of  the 
tree  with  the  bottom. 

5.  Are  they  all  equally  advanced  on  the  same  branch  ? 
On  the  same  twig  ?     Try  to  account  for  any  irregularity 
in  development  you  find. 

6.  Do  all  of  the  buds  develop  ?     What  is  the  location 
of  those  that  remain  dormant,  if  any  are  found  ? 

7.  Is  there  any  advantage  to  the  plant  in  having  dor- 
mant buds  ? 

8.  Cut  off  the  outer  end  of  a  few  twigs  and  watch  the 
effect  on  the  development  of  the  buds  that  remain.     Pick 
off  all  the  buds  from  a  few  twigs  and  watch  the  result. 

9.  What  is  the  function  or  use  of  the  terminal  buds  ? 
Look  for  the  former  positions  of  the  terminal  bud  on 
the  same  branch  ;  why  does  it  leave  a  scar  each  year  ? 

10.  What  is  a  bud  ?     To  answer  this,  examine  as  large 
a  one  as  you  can  find  (a  lilac  will  do)  that  is  just  begin- 
ning to  swell.     Dissect  a  bud  and  find  in  the  center  the 
tender  growing  point.     What  is  the  difference  between  a 
bud  and  a  seed  ? 

n.  Can  you  find  any  buds  on  the  trunk  of  a  tree? 
What  evidence  can  you  find  that  they  are  there  ? 

12.  Do  roots  produce  buds?     How  do  you  account 
for  sprouts  that  sometimes  come  up  from  the  roots  of 
trees  ? 

13.  Examine  some  of  the  fruit  trees  for  flower  buds; 
which  unfold  first,  flower  or  leaf-buds  ? 

14.  Do   you   find   any  buds   growing  about  the  same 
point  in  pairs  or  clusters?    Do  all  of  such  buds  develop  ? 

15.  Are  these  buds  always  arranged  in  the  same  way 


April]  BOTANY.  31? 

in  the  group?     Does  the  arrangement  differ  in  the  same 
plant  ? 

The  following  synopsis  of  the  terms  needed  in  the 
study  of  buds  is  appended  to  assist  the  teacher.  The 
proper  name  should  be  given  when  it  is  needed  in  de- 
scription. 

BUDS. 

I.  AS    TO    POSITION. 

1.  Terminal ;  at  the  end  of  the  twig. 

2.  Lateral ;  along  the  sides  of  the  twig. 

(a)  Axillary  ;  in  the  leaf-axil  ;  that  is,  the  upper 

angle  between  the  leaf  and  the  stem. 

(b)  Accessory  ;  buds  clustered  about  the  axillary 

buds. 

(c)  Adventitious;   buds  that   are   produced  ir- 

regularly on  the  branch  or  trunk.  Often 
develop  when  the  regularly  arranged  buds 
are  destroyed. 

Nodes  are  the  points  on  the  stem  at  which 
the  buds  are  produced  ;  inte modes,  the 
spaces  between  the  nodes. 

II.  AS  TO  ACTIVITY. 

1.  Active  ;  those  that  develop. 

2.  Dormant ;  those  that  form,  but  do  not  develop. 

Note  the  effect  on  these  of  destroying   the 
active  buds. 

III.  AS    TO  COVERING. 

1.  Scaly  ;  covered  with  dry,  tough,  bark-like  layers. 

2.  Naked  ;  without  scaly  covering. 

3.  Hidden  ;  those  buried  under  or  in  the  bark. 

IV.  AS  TO  ARRANGEMENT. 

i.  Opposite  ;  two  at  the  same  node  and  opposite. 


3l8  NATURE   STUDY.  [April 

2.  Whorled  ;  three  or  more  arranged  around  the 

same  node. 

3.  Alternate  ;  in  ranks  along  the  stem,  not  being 

opposite  or  whorled. 

UNDERGROUND  FORMS  OF  THE  PLANT  AXIS. 

This  season  of  the  year  is  an  appropriate  time  in 
which  to  study  underground  stems  and  those  roots 
which,  preserved  through  the  winter,  are  now  ready  to 
send  forth  vigorous  growths  and  make  woodland  and 
meadow  gay  with  early  flowers.  As  great  a  variety  as 
possible  should  be  collected. 

1.  If  they  grow  in  the  neighborhood,  gather  the  under- 
ground part  of  the  common  blue  flag  (the  iris),  or  calamus 
(sweet  flag),  Solomon's  seal,  or  blood-root.     Are   these 
roots  or  stems  ?     What  evidence  can  you  find  on  either 
side  ?     Can  you  find  any  evidence  as  to  how  long  they 
have  been  growing  ? 

2.  Compare  these    with    the    common    potato  ;    what 
differences   do   you    find  ?     What   are   the  eyes  of  the 
potato  ?     Plant  some  of  these  and  watch  how  and  where 
the  young  potatoes  are  formed.     What  becomes  of  the 
old    potato  ?      The  potato    and   all    underground    parts 
like  it  are  called  tubers.     Those  like  the  blue  flag  are 
called  rhizomas. 

3.  Examine  the   thickened    underground    part  of  an 
Indian  turnip  (Jack-in-the-pulpit).     How  does  it  differ 
from  a  tuber  or  a  rhizoma  ?     It  is  called  a  corm. 

4.  Examine  the  underground  part  of  a  lily  or  an  onion. 
Cut  it  so  as  to  make  various  sections  ;  what  part  of  a 
plant  does  it  most  resemble  ?     What  part  of  the  plant 
forms   the  overlying  scales  of  the  onion  ?     What  forms 
its  solid  base  from  which  roots  are  produced  ?     Under- 


April]  BOTANY.  3X9 

ground  parts  like  the  lily  and  onion  are  called  bulbs. 
How  do  they  differ  from  the  forms  previously  examined  ? 
What  have  they  in  common  with  them  ?  An  onion  is 
called  a  tunicated  bulb  ;  in  the  lily  bulb  and  others, 
where  the  layers  are  small,  it  is  said  to  be  scaly. 

5.  Examine  the  underground  parts  of   the   hepatica 
or  buttercup  ;   how  do  these  differ  from  those  first  ex- 
amined ?     Are  they   roots  or  stems  ?     Where  they  are 
clustered  in  this  way  they  are  said  to  be  fascicled.  Where 
they  are  thickened  they  become  tuberous. 

6.  Can  you  find  any  plants  with  a  main  root  growing 
straight  downward  ?     This  is  called  a  tap  root.     These 
become   thickened   sometimes  so  as  to  become  conical, 
spindle-shaped,  napiform,  or  turnip-shaped.     What  ex- 
amples of  these  can  you  find  among  our  common  vege- 
tables ? 

7.  Do  stems  ever  produce  roots  above  ground  ?     Un- 
der what  conditions  and  for  what  purposes  ? 

8.  Can  you  see  what  features  distinguish  a  root  from 
a  stem  ? 

9.  Can  you   understand  why  such  plants  as  many  of 
those  mentioned  above  can  produce  early  flowers? 


In  continuing  the  study  of  Light  this  month,  we  shall 
find  that  images  may  be  formed  in  a  very  different  way 
from  that  by  which  they  were  produced  with  mirrors.  In 
.their  explanation,  however,  it  will  be  seen  that  nothing 
is  involved  that  has  not  already  been  considered  in 
previous  lessons,  except  the  fact  of  refraction  and  its  laws. 
If  the  work  indicated  for  the  preceding  month  has  been 
well  illustrated,  no  difficulty  will  be  found  here. 

1.  Through  a  small  hole  in  the  window  shutter  admit 
a  beam  of  sunlight  into  a  darkened  room;  allow  it  to 
strike  the  side  of  a  glass  vessel  filled  with  water.     A  use- 
ful tank. for  this  purpose  can  be  made  by  any  tinner  for 
a  few  cents.     It  should  be  about  six  inches  long  by  four 
in  depth  and  width.     The  bottom  and  ends  should  be 
made  of  tin,  with  edges  turned  in  so  as  to  admit  of  glass 
sides  beingslipped  in.     Putty  well  on  the  inside.     A  large 
square  bottle  of  clear  glass  will  .answer  the  purpose  of 
the  tank  very  well. 

2.  Hold  the  vessel   so  that  the  beam   will  strike  the 
sides   perpendicularly ;  can   you   trace   the   path  of  the 
beam  through  the  water  ?     Can  you  trace  it  after  it  leaves 
the  water  on  the  opposite  side  ? 

3.  Notice  the  kind  of  a  line  it  follows  from  the  point 
where  it  enters  the  room  to  the  place  where  it  should 
strike  the  wall  or  a  screen  beyond  the  vessel  of  water. 

4.  Hold  the  vessel  so  that  the   beam  will  strike  the 
sides  at  an  acute  angle  ;  follow  its  course  through  the 
water  and  to  the  screen.     Do  you  notice  any  change  in 

320 


April]  PHYSICS.  321 

its  course  ?     Compare  its  course  with  that  which  it  follows 
in  the  air. 

5.  Turn  the  tank  around  on  a  vertical  axis  and  watch 
the  path  of  the  ray  ;  upon  what  does  its  variation  from  a 
straight  line  depend  ? 

6.  A  beam  of  light  thus  bent  from  a  straight  course 
when  it  passes  into  or  through  different  substances  is  said 
to  be  refracted.     What  difference  do  you  see  between  re- 
fraction and  reflection? 

7.  The  direction  in  which  a  beam  of  light  is  refracted  is 
always  referred  to  a  normal  (see  22,  Physics  for  March) 
drawn  (within  the  refracting  substance)  to  the  point  on 
the  surface  where  the  beam  enters  it.     When  the  beam 
enters  the  water  in  the  vessel,  is  it  refracted  toward  or 
away  from  the  normal  ? 

8.  Draw  a  normal  to  the  point  where  the  beam  enters 
the  air  again  ;  in  what  direction  is  the  beam  refracted  ? 
Turn  the  tank  or  vessel  in  different  directions  ;  can  you 
find  a  position  where  the  refracted  beam  does  not  take 
the  same  direction  with  respect  to  the  normal  ? 

9.  Is  there  any  position  in  which  the  beam  is  not  re- 
fracted at  all  ? 

10.  Place  the  end  of  a  pencil  or  stick  in  a   vessel  of 
water  ;  what  do  you  notice  at  the  point  where  it  enters 
the  water  ? 

n.  Make  a  drawing  of  the  vessel,  the  water  and  pencil, 
and,  by  lines,  show  the  course  of  the  rays  of  light  that 
passed  upward  through  the  water  from  the  pencil.  Do 
you  see  the  pencil,  or  its  image,  below  the  surface  ? 

12.  In  a  tin  cup,  place  a  penny  and  hold  it  so  that  it  can- 
not be  seen  when  looking  across  the  rim  into  the  vessel. 
Cautiously  add  water,  and  watch  for  the  appearance  of 
the  penny.  Is  it  the  penny  or  its  image  that  appears  ? 


322  NATURE   STUDY,  [April 

13.  As  in  (u),  make  a  drawing  showing  the  course  of 
a  ray  of  light  from  the  penny  to  the  eye. 

14.  Is  it  the  reflected  or  refracted  part  of  the  ray  from 
the  penny  that  brings  what  we  see  into  view  ? 

15.  Hold  an   ordinary  lens  or  magnifying  glass   be- 
tween the  sun  and  a  sheet  of  paper  ;  move  the  paper  back 
and  forth  until  the  light  spot  is   brightest  and  smallest. 

16.  How  large  in  diameter  is  the  beam  of  light  from 
the  sun  that  strikes  the  surface  of  the  lens  ?    Why  should 
it  be  conveyed   to  a  point  by  passing  through  the  lens? 
Before  trying  to  answer  this,  examine  the  lens ;  what  do 
you  notice  about  its  surfaces  ?     Draw  a  vertical  section 
so  as  to  show  the  curvature  of  both  surfaces  ;  construct 
lines  which    will   be    normals  to  different    parts  of  the 
surface  ;  are  they  parallel  ?     If  not,   where  would  they 
meet  ? 

17.  Is  any  line  that  is  normal  to  one  surface,  normal 
also  to  the  other  ? 

18.  In  a  drawing  similar  to  the  one  above,  draw  a  line 
on  one  side,  representing  a  ray  of  light  to  the  lens  some- 
where between  its  center  and  circumference  ;  construct 
normals  and  show  what  its  path  would   be  on   entering 
and  leaving  the  lens.     To  another  point  on  the   same 
side  of  the  lens  draw  a  line  representing  another  ray,  and 
in  the  same  way  show   its  course  through  the  lens  and 
beyond.      What   is   the  relation  of  the   two  lines  after 
leaving  the  lens  ?     Can  you  now  account  for  the  bright 
spot  observed  in  (15)  ? 

19.  Take  a  thin  strip  of  wood  three  inches  wide  and 
two  and  a  half  feet  long.     Mark  off  one  side  in  inches. 
In   any  convenient  way  mount  a  common   single  lens 
magnifying  glass  so  that  the   light  will  pass  through  it 
horizontally  and   fall  upon  a  screen.      The  latter  may 


April]  PHYSICS.  323 

consist  of  a  piece  of  card-board  six  inches  square.  A 
low  block  with  a  groove  sawed  in  it  to  recive  the  card- 
board, which  may  be  fastened  with  glue  or  a  tack,  will 
make  a  support. 

20.  Place  the  lens  and  screen  on  the  strip  of  wood. 
On  the  opposite  side  of  the  lens  from  the  screen,  place  a 
small  lighted  candle,  and  move  it  into  a  position  where 
it  will  throw  an  image  on  the  screen.     With  which  kind 
of  mirror  was  a  similar  image  formed  ? 

21.  Make  a  diagram  of  the   lens,  object,  and   image, 
and    trace   (see   32,  Physics  for    March)  lines  showing 
the  course  of  the   rays  of  light  from  the  object  to   the 
image. 

22.  Place  the  lens  so  that  the  size  of  the  image  is  the 
same  as  that  of  the  object  ;  draw  lines  showing  why  this 
is  so. 

23.  Place  object  and  lens  in  such  a  position  that  the 
image  is  less   than  the  object  ;  can  you   show  by  lines 
why  it  is  smaller  ?     Is  the  image  formed  in  each  of  these 
experiments  real   or  virtual  ?      In   what  ratio  does   the 
image   vary  with  the  distance  of   the  object  from  the 
lens? 

24.  Look  through  the   lens  at  a  letter  or  other  small 
object  ;  do  you  see  the  object,  or  an  image  ? 

25.  Prove  by  lines  which  it  is.     If  it  is  an  image,  is  it 
real  or  virtual  ?     Why  is  it  enlarged  ?     Prove  by  drawing 
lines  showing  their  path  of  light  from  the  object  to  the 
eye. 

26.  Admit  a  beam  of  light  through  a  small  hole  in  the 
window   shutter.     Hold    a   screen    so   as  to   catch    the 
spreading  rays  ;  can   you   see  the  image   of  any  objects 
outside  ? 

27.  Compare  the  image  in   position,  size,  etc.,  with  the 


324  NATURE   STUDY.  [April 

object ;  how  does  moving  the  screen  backward  and  for- 
ward affect  it  ? 

28.  Why  should  an  image  form  under  these  conditions  ? 
Make  a  diagram  showing  by  a  vertical  section  the  posi- 
tion of  the  object,  the  shutter,  and  the  image   on  the 
screen  ;  recall  what  was  learned  in  March  about  reflec- 
tion and  the  visibility  of  objects. 

29.  Allow  a  small  sunbeam  to  pass  through  a  prism  (for 
directions  for  making  one,  see  Physics  for  September). 

30.  Note  the  rays  that  fall  upon  the  screen,  and  com- 
pare with  the  sunbeam.     How  many  colors  can  you  dis- 
tinguish ?     In  a  diagram,  show  the  course  of  the  beam 
through  the  prism. 

31.  Catch  all  these  colored  rays  on  a  concave  mirror, 
and  reflect  them  to  a  screen  ;  what  color  is  the  light  at  the 
focus  ?     What  does  this  prove  as  to  the  sunbeam  before 
it  strikes  the  prism?     Which  rays  are  most  refracted  as 
they  leave  the  prism  ?     Which  the  least  ? 

32.  Hold  some  white  object  in  the  red  rays  ;  what  color 
does  it  appear  to  be  ?     Try  in  the  same  way  the  different 
colored  rays ;  what  is  it  in  this  case  that  seems  to  deter- 
mine its  color  ? 

33.  What  colored  rays  are  carried  to  the  eye  in  each 
case  ?     When  the  sunbeam,  not  refracted,  falls  on  the 
object,  what  color  does  it  appear  to  be  ? 

34.  In  ordinary  daylight  look  at  some  red  object  ?  what 
kind  of  light  strikes  it  ?     What  kind  must  be  cliff  used  from 
it?     Try   in  the  same  way  objects  of  different  colors. 
The  rays  not  sent  to  the  eye  from  the  object  are  ab- 
sorbed by  it. 

35.  What  colored  rays   are  absorbed   by  an  orange? 
What  ones  are  absorbed  by  a  white  surface  ?     By  a  black 
surface  ? 


April]  PHYSICS.  325 

36.  Is  color  something  belonging  to  the  object  itself? 

37.  Can  you  apply  what  you  have  learned  about  refrac- 
tion of  light  by  a  prism,  to  show  how  a  rainbow  is  formed  ? 
Under  what  conditions  is  it  seen  ?    Make  a  diagram  show- 
ing the  relative  position   of  the  bow,  the  sun,  and  the 
observer. 

38.  What  is  there  in  the  atmosphere  to  break  the  sun- 
light up  into  the  colored  rays  ?     How  are  these  rays  di- 
rected to  the  eye  of  the  observer  ? 

39.  Can  you  give  a  reason  why  the  colors  in  the  rain- 
bow stand  in  the  order  in  which  you  see  them? 

40.  Why  is  the  rainbow  in  the  form  of  an  arc  of  a  cir- 
cle ?     Did  you  ever  see  one  in  form  of  a  circle,  entirely 
above  the  horizon  ?     Why  ?     Have  you  ever  seen  one  at 
noon  ?     Have  you  ever  seen  one  in  the  west  ? 

41.  Can  you,  from  what  you  have  learned,  give  any 
satisfactory    explanation   of  rings  around  the  sun    and 
moon? 


WATER. 

1.  Dissolve  a  small  quantity  of  salt  in  a  bottle  or  test- 
tube  of  water  ;  when  the  salt  disappears,  is  it  destroyed  ? 
Is  it  changed  to  anything  else  ?     Proof.      Has  it  united 
with  the  water  ? 

2.  Fit  a  bent  tube  through  a  cork  that  will  fit  the  flask 
or  test  tube  and  gently  heat  it  over  your  lamp.     Hold  the 
vessel  in  such  a  position  that  the  steam  that  comes  through 
the  tube  may  be  caught  in  a  cool   receiver.     Taste  the 
drops  of  water  that  soon  appear  ;  are  they  fresh  or  salty  ? 
Does  this  enable  you  to  answer  the  last  question  in  (i)? 

3.  What  is  this  process  called  ?     (See  Physics  for  Oc- 
tober.) 

4.  Take  a  small  piece  of  perfectly  clean  glass  ;  place 
upon  it  a  large  drop  of  hydrant  or  spring  water,  and  hold 
it  over  the  lamp  until  it  has  evaporated.     Is  there  any  de- 
posit left  on  the  glass?     What  is  it  ?     Can  you  burn  it  in 
the  flame  ?    What  does  the  burning  or  the  failure  to  burn 
prove  ? 

5.  Take  a  drop  of  the  purest  filtered  water  you  can  get 
and  evaporate  it  as  in  (4)  ;  is  there  any  solid  matter  left  ? 

6.  What  is  removed  from  water  by  filtering  it  ?     What 
still  remains  in  it  ?     Try  filtering  a  salt  solution,  using 
filter   paper.      (See  19,  Chemistry  for  February.)     Can 
you  taste  the  salt  in  the  filtrate,  that  is,  in  the  filtered 
part? 

326 


April]  CHE  MIS  TRY.  327 

7.  Distil  some  hydrant  or  spring  water  as  directed  in 
(2)  and  evaporate  on  your  glass  some  of  the  drops  formed 
from  the  steam  ;  is   there  any  deposit  left  ?     What  did 
distillation  do  for  the  water  ? 

8.  How  and  where  is  distillation  of  water  carried  on  in 
nature  ? 

9.  When  it  rains,  catch  in  a  perfectly  clean  vessel  some 
rain  water  ;  evaporate  a  drop  of  this  in  your  glass.     Is 
there  any  solid  matter  left  ?     Compare  it,  as  to  purity, 
with  hydrant  water  filtered. 

10.  How  does  spring  water  gather  its  solid  matters  ? 
What  parts  cannot  be  filtered  out  ? 

11.  Powder  a  small  lump  of  gypsum,  and  add  it  to  a 
bottle  of  rain   water,  or  distilled  water.     Shake  it  thor- 
oughly and  filter  ;   are  there  any  traces  of  the  gypsum 
visible  in  the  filtrate  ? 

12.  Dissolve   some   soap   in    hot  water  and  keep  the 
solution  in  a  bottle  labeled  Soap  Solution. 

13.  Add  a  little  of  the  soap  solution  to  a  test  tube  of 
distilled,  or  rain  water,  and  shake  it.     Add,  also,  some 
of  the  soap  solution  to  the  filtrate  obtained  in  (n)  ;  what 
difference  do  you  notice  in  the  two  tubes?     The  first  is 
called  soft  water,  the  latter  hard  water. 

14.  Boil  some  of  the  filtrate,  and  then  add  soap  solu- 
tion ;  does  boiling  affect  the  hardness  ? 

15.  Take  a  tumbler  of  lime-water  and  blow  your  breath 
into  it  through  a  tube  ;  recall  an  experiment  in  Chemistry 
for  November.     (See  24,  Chemistry  for  November.) 

16.  Continue  blowing  until  the  water  clears ;  this  may 
take  some  minutes.     Filter. 

17.  Divide  the  filtrate,  and  test  one  part  with  the  soap 
solution  ;  is  it  hard  or  soft  water  ? 

18.  Boil  the  other  part  of  the  filtrate,  and  test  with 


328  NATURE   STUDY.  [April 

soap    solution  ;    compare   with    what  you    observed    in 

(-7). 

19.  The  hard  water  containing  gypsum  is  said  to  be 
permanent   hard   water ;    that   containing   limestone  or 
chalk,  is  temporary  hard  water. 

20.  The  explanation  of  the  formation  of  hard  water  in 
the  second  instance  is  this  :  the  carbon  dioxide  from  the 
breath  unites  with  the  lime  in  the  water  and  forms  car- 
bonate of  lime.     By  continuing  the  blowing  the  excess 
of  carbon  dioxide  dissolves  the  carbonate,  and  the  water 
containing  this  in  solution  is  hard. 

21.  Can  you  see  why  boiling  temporary  hard  water 
renders  it  less  hard  ? 

22.  Add  to  some  of  the  filtrate  obtained  in  (16)  some 
clear  lime-water  ;  when  the  mixture  clears,  test  a  little 
of  the  clear  part  with  the  soap  solution  ;  is  it  soft  or 
hard  ?     Explain. 

23.  Which  requires  the  greatest  amount  of  soap  to  be 
used  in  washing,  hard  or  soft  water  ?     What  difference 
do  you  notice  in  the  feel  of  the  two  kinds  of  water  ? 

24.  An  interesting  test  for  a  small  quantity  of  salt  in 
water  may  be  made  as  follows  :  Put  a  ten-cent  piece  into 
a  small  amount  of  dilute  nitric  acid  ;  when  it  is  dissolved, 
evaporate  the  solution.     Redissolve  the  crystals  formed 
in  distilled  water.     This  is  silver  nitrate,  which  also  con- 
tains some  copper  which  gives  the  bluish  tinge.     Bot- 
tle, in  a  clean  dark-colored  bottle,  or  else  keep  in  the  dark. 
Label  it  properly. 

25.  Thoroughly  wash  and  rinse  two  bottles  or  tumblers, 
and  partly  fill  each  with  pure  distilled  water.     In  one, 
dissolve  a  piece  of  salt  about  the  size  of  a  pin-head. 

26.  Add  a  drop  or  two  of  the  silver  nitrate  to  the 
beaker  of  pure  water  ;  can  you  notice  any  change  ? 


April]  CHEMIS  TRY.  329 

27.  Add  a  drop  or  two  to  the  vessel  containing  the 
grain  of  salt  ;  what  change  do  you  notice  ? 

28.  With  the  silver  nitrate  test  the  hydrant  water,  rain 
water,  spring  water,  and  well  water,  if  it  can   be   ob- 
tained. 


Meteorology 

The  meteorological  influences  of  April  are  usually  of 
a  very  different  kind  from  those  of  the  preceding  months. 
For  six  months  they  have  been  negative  in  character, 
but  from  now  forth  they  are  positive  ;  they  no  longer 
play  the  part  of  a  destroyer,  but  rather  that  of  a  creator. 
These  benign  influences  are  to  be  seen  and  felt  by  all, 
and  the  pupils,  properly  guided,  will  be  interested  in 
tracing  them  to  their  cause. 

1.  Can  you  notice  any  difference  in  the  character  of 
the  wind  this  month  ?     To  what  is  the  difference  due  ? 

2.  What  is  the  prevailing  direction  of  the  wind  ?     Has 
it  changed  within  the  last  month  ? 

3.  In  what  month  studied  has  the  wind   been  most 
variable  ? 

4.  Is  the  prevailing  wind  accompanied  by  wet  or  dry 
weather  ?      Can   you   give  a   reason   for  the   observed 
facts  ? 

5.  What  wind  usually  accompanies  a  clear  sky  ?  Com- 
pare with  previous  months. 

6.  Are  the   clouds   changed   in   their  character   this 
month  ?     Notice  their  height  and  compare  with  previous 
months. 

7.  Compare  the  fogginess  of  this  month  with  that  of 
preceding   ones  ;  can   you   account   for   the   difference 
noticed  ? 

8.  Under  what  conditions  are  the  heaviest  fogs  formed? 
What  conditions  about  you  are  especially  favorable  for 

330 


April]  METEOROLOGY.  331 

their  formation  ?     When  fogs  disappear,  what  becomes 
of  them  ? 

9.  What  difference  do  you  notice  between  April  rains 
and  those  of  the  winter  months  ? 

10.  How  does  the  amount  of  rainfall  now  compare 
with  that  of  October  ?     With  December  ? 

n.  Compare  the  number  of  rainy  and  clear  days  with 
that  of  previous  months. 

12.  Compare  the  temperature  of  this  month  with  that 
of  March. 

13.  In  what  autumn  month  did  the  earth  occupy  the 
same  relative  position  with  respect  to  the  sun  ?  Compare 
the  temperature  for  the  two  months.     How  does   the 
rate  of  change  correspond  ? 

14.  Compare  the  rate  of  change  in  temperature  this 
month  with  that  for  March. ' 

15.  What  wind  accompanies  the  highest  temperature  ? 
The  lowest  ?     Compare  with  March  and  December. 

16.  What  is  the  greatest  range  in  the  movement  of  the 
barometric  column  ?     Compare  with  March  and  Octo- 
ber. 

17.  Has  there  been  any  uniformity  in  the  barometric 
record  just  before  storms  ? 

18.  Does  the  movement  of  the  barometric  column  cor- 
respond in  any  way  to  that  of  the  thermometer  ? 

19.  Have   there   been   any   mornings   without   either 
frost  or  dew  ? 

20.  Can  you  find  any  places  where  the  ground  is  still 
frozen  ? 

STUDY  OF  THE  WEATHER   BUREAU  MAPS. 

21.  What  isotherm  crosses  nearest  where  you  live  this 
month  ?     Is  it  changing  its  position  in  either  direction  ? 


332  NATURE    STUDY.  [Apru 

22.  What  isotherm  crosses  the  Gulf  States  ?     Compare 
with  March. 

23.  Compare  the  position  of  the  isotherms  that  cross 
the  country  this  month,  with  those  of  the  month  referred 
to  above  in  (13).     Try  to  explain  any  difference  noticed. 

24.  Where  have  the  Low  Areas  generally  been  formed 
this  month  ?     Compare  with  March. 

25.  What  has  been  the  direction  of  the  great  storms  ? 
Can  you  notice  any  difference  from  that  of  preceding 
months  ? 

26.  Compare  the  temperature  of  the  Low  Area  with  that 
of  the  High  Area  ;  does  it  bear  the  same  relation  that  it 
did  in  preceding  months? 

27.  In  what  quarter  of  the  country  has  there  been  the 
heaviest  rainfall?     Compare  with  the  autumn  month  re- 
ferred to  above  in  (13). 

28.  In    what    place  does  the   heaviest   rainfall  occur 
with  respect  to  the  Low  Area  ? 

29.  What  is  the  uniform  direction  of  the  wind  about 
the  Low  Area  ?     Have  you  found  any  exceptions  to  the 
rule? 

30.  Do  the  Great  Lakes  appear  to  affect  the  course  of 
the  storms  ?     Note  the  effect  of  the  mountains,  valleys, 
and  coast  lines. 


astronomy 

In  view  of  the  importance  of  the  point  to  be  enforced, 
it  will  not  be  considered  out  of  place  here  to  speak  spe- 
cifically of  what  has  been  hinted  at  before  concerning  the 
proper  use  of  symbols  and  diagrams  in  illustrating  this 
subject.  The  teacher  should  sharply  discriminate  be- 
tween the  pupil's  ability  to  comprehend  an  illustration,  a 
mere  device,  and  his  power  to  grasp  or  form  a  concept 
of  the  real  thing  to  be  taught.  A  pupil,  pointer  in  hand, 
may  glibly  explain  a  diagram  on  the  blackboard  which 
illustrates  the  various  movements  of  the  heavenly  bodies 
and  their  mutual  relations,  without  having  the  faintest 
glimmer  of  those  great  educative  conceptions  of  space, 
time,  and  force,  which  are  the  true  outcome  of  the  study 
when  properly  conducted.  Specific  rules  of  procedure 
which  will  suit  all  cases  cannot  be  given  ;  it  should  be 
constantly  borne  in  mind,  however,  that  the  true  ideas 
must  come  from  small  beginnings,  but,  if  properly  started, 
they  will  be  of  perennial  growth.  Something  which  falls 
within  the  bounds  of  the  pupil's  experience  should  be 
seized  upon,  and  from  it  his  mind,  unaided,  should  be 
led  outward  toward  the  source  of  the  phenomenon  to  the 
very  limit  of  his  power  of  thought,  and  then,  only,  may 
a  device  be  relied  upon  to  safely  perform  its  proper  func- 
tion of  illustration. 

i.  Compare  the  movement  of  the  noon  shadow  with 
that  of  last  month  ;  what  do  you  notice  about  the  rate 
of  movement  ? 

333 


334  NATURE   STUDY.  [April 

2.  With  what  previous  month  do  the  marks  most  nearly 
coincide  ? 

3.  How  does  the  rate  of  movement  correspond  with 
that  of  the  same  month  ? 

4.  Is  the  rate  of  movement  of  the  noon  shadow  increas- 
ing or  diminishing  ? 

5.  What   angle  do  the  sun's  rays  now  make  with  the 
earth  ?     Compare  with  December. 

6.  If  the  apparent  path   of  the  sun  could  be  traced 
across  the  heavens  daily,  what  kind  of  a  line  would  be 
formed  ? 

7.  Can  you   determine  from*  a   measurement  of   the 
angle  of  the  noon   shadow  how  high  the  sun  would   ap- 
pear to  one  at  the  North  Pole  ?     How  high  would  it  ap- 
pear to  one  on  the  Arctic  circle  at  noon  ? 

8.  Where  on  the  globe  is  the  longest  day  at  this  time  ? 
Explain  why  it  is  so. 

9.  Where   is   the   shortest  day  ?      Are  the  days   and 
nights  equal  in  length  anywhere  ? 

10.  How  many  degrees  on  the  horizon  has  the  sun 
moved  since  the  vernal  equinox  ?     How  many  degrees 
has  it  climbed  the  meridian  in  the  same  time  ? 

11.  How  many  degrees  has  it  moved  on  the  horizon 
since  the  winter  solstice  in  December? 

12.  Is  the  rate  of  change  in  the  day's  length  increasing 
or  diminishing?     Explain  why  this  is  so. 

13.  Is  the  increase  of  the  day's  length  made  by  equal 
additions  morning  arid  evening? 

14.  When  are  the  variations  at  morning  and  evening 
most  nearly  equal  ?    When  are  they  most  unequal  ? 

15.  In  what  part  of  the  year  is  the  variation  greatest 
in  the  morning  ?     When  is  the  variation  greatest  at  even- 
ing ? 


April]  ASTRONOMY.  335 

16.  To  what  causes  are  the  differences  noted  in  (15) 
due? 

17.  About  the  middle  of  this  month  it  will  be  noticed 
that  Mercury  appears  as  evening  star.     How   have  the 
earth  and  it  changed  in  relation  to  each  other  since  it 
was  seen  as  morning  star  ?     (See  Astronomy  for  Febru- 
ary). 

18.  Additional  constellations  :  Crater;  Berenice's  Hair. 

REFERENCE.     Humboldt  Library  :  No.  14,  Wonders  of  the  Heavens. 


(Beograpbp, 


EURO-ASIA.     PRODUCTIONS. 

1.  Where  are  the  greatest  differences  in  productions 
between  the  northern  and  southern,  or  eastern  and  west- 
ern divisions  of  this  great  continent  ?     Why  ? 

2.  What  contrasts   are  presented  in  the  productions 
between  those  of  the  coast  and  the  interior  ? 

3.  Does   the    eastern   or   western    coast   differ   more 
widely  from  the  interior  in  productions.     Why  ? 

4.  Are   the  river  valleys  important    in    their  bearing 
upon  the  productions  ?   Which  ones  are  most  important  ? 

5.  Where  is  the  most  important  grain  region  ?     What 
conditions  favor  it  ?     What  cities  lead  in  grain  exports  ? 

6.  Is  the  grain  region  found  in  the  same  latitude  in  the 
different  parts  of  the  continent  ? 

7.  Compare  the  latitude  of  the  grain  districts  in  Euro- 
Asia  wifrh  that  of  North  America. 

8.  Where  are  the  timber  regions  of  Euro- Asia  ?    What 
varieties  are  to  be  found  ?     What  are  the  climatic  condi- 
tions found  in  a  timber  region  ? 

9.  How  does  the  character  of  the  forests  in  the  north- 
ern latitudes  differ  from  that  of  those  in  the  southern  ? 

10.  Compare  the  latitude  of  the  northern  timber-line 
in  Euro-Asia  with  that  of  North  America  ;  how  can  you 
account  for  the  difference  noticed  ? 

11.  What  differences  are  there  between  the  produc- 

336 


April]  GEOGRAPHY.  337 

tions  of  the  Mediterranean  countries  and  those  of  south- 
ern Asia  ?  What  influences  combine  to  give  them  some 
similarity?  What  is  the  difference  in  latitude? 

12.  In  what   regions  are  the  fruits  of  the  temperate 
zone  grown  ? 

13.  Where  are  the  vine,  the  olive,  and  fig  cultivated  ? 
Compare  with  the  same  latitude  of  North  America.     To 
what  is  the  great  contrast  chiefly  due  ? 

14.  Where  are  the  great  meadow-lands  of  Euro  Asia  ? 
Which  do  these  more  closely  resemble,  those  of  North 
America  or  South  America  ? 

15.  In  which  of  the  three  continents  mentioned  in  (14) 
is  the  character  of  the  productions  mostly  dependent  upon 
latitude? 

16.  Compare  the  effects  of  the  great  mountain  ranges 
in  these  continents  upon  the  productions. 

17.  Locate   the  chief   mineral    regions  of  Euro- Asia. 
What  minerals  are  of  most  importance  ? 

18.  What  ones  of  value  in  the  Ural  Mountains? 

19.  Where   are    precious    stones   found?     Where    are 
gold  and  silver  found  ? 

20.  Where  are  the  valuable  iron  mines?     Coal  mines  ? 
Where  is  tin  found  ? 

21.  Does  the  character  of  the  productions  of  a  country 
make  its  impress  upon  the  people  ?     Compare  the  agri- 
culturists  of    Europe  with   those  that  work    in    mines  ; 
what  differences  in  their  character  are  due  to  their  differ- 
ent occupations? 

22.  Where  are  the  most  thrifty  peoples  of  Euro-Asia 
located  ?     Is  their  thrift  due  to  any  extent  to  the  kind  of 
productions  in  their  countries  ? 

23.  What   is  the  character  of  the  vine-growers  ?     Of 
the  grain-raisers? 


338  NATURE  STUDY.  [April 

* 

24.  Is  the  intelligence  of  a  people  in  any  great  measure 
dependent  upon  the  productions  of  the  countries  in  which 
they  live  ?     Illustrate  the  point  in  Euro-Asia. 

25.  Are  the  conditions  of  the  present  tending  to  reduce 
or  increase  the  importance  of  the  relation  which  exists 
between  the  character  of  a  people  and  the  productions  of 
their  country  ? 


Last  month  we  considered  the  geological  importance 
of  an  organism  which  has  done,  in  connection  with  other 
creatures  of  the  same  character,  a  work  almost  inconceiv- 
ably vast  in  making  the  earth's  crust  what  it  is.  This 
month  we  must  consider  the  work  of  another  class  of 
organisms,  which  is  of  less  extent,  perhaps,  but  hardly  less 
interesting.  The  study  relates  to  the  work  that  plants  are 
doing,  and  have  done,  when  under  certain  conditions,  at 
building  on  the  earth's  surface.  The  work  should  be 
preceded  by  a  visit  to  a  swamp,  and  as  close  a  study  of 
it  as  the  age  and  experience  of  the  pupils  will  warrant. 

1.  What  are  some  of  the  conditions  which  have  caused 
the  swamp  ? 

2.  Is  it  the  result  of  a  stream  or  a  lake  ?     Is  it  being 
filled  by   sediment  that  is  washed  in  from  the  adjacent 
land? 

3.  Examine   some   of   the   mud  ;  what   is  its   color  ? 
Does  it  consist  of  sand  grains  ? 

4.  Is  it  like  clay  mud  found  in  drier  places  in  times  of 
wet  weather  ?     Dry  some  of  it,  and  compare  with  clay 
and  sand. 

5.  Using  a  pole  as  a  probe,  can  you  tell  how  deep  it  is  ? 

6.  Where  does  the  soft  material  come  from  that  is  not 
washed  in  from  adjacent  higher  ground  ? 

7.  Can  you  find  the  remains  of  either  animals  or  plants 
in  the  mud  ?     Do  they  seem  to  be  decaying  ? 

8.  In  some  of  the  great  bogs  of  the  world,  some  marvel- 
ously  well  preserved  specimens  have  been  found.      "  In 

339 


34°  NATURE  STUDY.  [April 

1747,  in  an  English  bog,  the  body  of  a  woman  was  found, 
with  skin,  nails,  and  hair  almost  perfect,  and  with  sandals 
on  her  feet.  In  Ireland,  under  eleven  feet  of  peat,  the  body 
of  a  man  was  found  clothed  in  coarse  hair-cloth."  (Le 
Conte.) 

9.  Can  you    tell  what  effect  the  vegetation  that  now 
covers  the  swamp  has  upon  it  ? 

10.  Can  you  tell  whether  the  vegetation  ever  differed 
from  what  it  now  is  ?     Was  it  a  swamp  when  the  vegeta- 
tion differed  ? 

11.  Does  the  vegetable  matter  decay  as  it  falls  to  the 
earth  each  year  ? 

12.  When  the  black   material   of  which  the  swamp  is 
composed  is  dried  and  ignited,  will  it  burn  ? 

13.  If  it  burns,  what  does  this  show  its  history  to  be  ? 

14.  Peat  swamps  are   found   in   Ireland,  France,  and 
many  other  parts  of  middle  and  northern  Europe.     They 
are  much  more  abundant  in  the  north  than  in  the  south. 
They  are  rarely  found  south  of  36°  latitude. 

15.  The   Great  Dismal    Swamp  of  Virginia  is  an  ex- 
ception.    It  is    forty   miles   in   length,  north  and  south, 
and  twenty-five  miles  wide.     There  is  a  depth  of  fifteen 
feet  .of  vegetable  matter. 

16.  Why  is  it  that  peat  bogs  are  much  more  common  in 
the  north  than  in  the  south  ? 

17.  What   kind  of  climate  would  be  best  for  them  ? 
Why  ?     The  peat   formation  in   the    Dismal   Swamp    is 
rendered  possible  by  the  large  trees  with   dense  foliage 
which  grow  there.     Can  you  see  a  reason  ? 

18.  What  happens  to  vegetation  that  falls  to   ground 
in  the  southern  or  very  warm  countries  ? 

19.  Can  you  picture  to  yourself  how  it  would  be  possible 
for  a  peat  bog  to  be  transformed  into  a  coal  bed  ? 

20.  Where  is  peat  now  used  largely  as  fuel  ? 


Pupils  are  always  greatly  interested  in  making  those 
tests  which  produce  some  mysterious  changes  in  the  sub- 
stance used.  It  is  often  not  possible  for  them  to  under- 
stand what  those  changes  really  are  (who  does  under- 
stand them  ?),  but  such  work  is  stimulative  of  thought 
and  inquiry,  and  is  perfectly  legitimate  with  those  pupils 
who  can  handle  the  material  and  apparatus  themselves. 
Through  this  kind  of  work  will  be  acquired  the  habit  of 
carefully  examining  such  things  as  come  under  their 
notice,  and  also  the  skill  necessary  to  enable  them  to  do 
so.  The  outcome  of  the  habit  is  self-reliance,  a  factor  of 
inestimable  worth  in  the  make-up  of  character.  The 
apparatus  needed  for  certain  instructive  flame-tests  is  so 
simple  that  no  pupil,  even  in  remote  country  districts, 
need  be  without  the  means  of  informing  himself  of  im- 
portant and  interesting  properties  of  all  the  different 
minerals  in  his  locality.  Directions  for  making  an 
alcohol  lamp  are  given  under  Chemistry  for  November. 

A  small  pair  of  sharp-pointed  steel  forceps  or  tweezers, 
such  as  are  in  common  use  by  jewelers,  will  be  useful, 
it  may  be  said,  a  necessity.  In  addition,  there  should 
be  provided  two  pieces  of  hard  glass  tubing,  each 
about  three  inches  long,  one  closed  at  one  end  and  the 
other  open  at  both  ends.  A  few  small  pieces  of  red  and 
blue  litmus  paper  will  also  reveal  interesting  facts  about 
some  minerals  when  heated  in  the  tubes.  Enough  may 

341 


342  NATURE   STUDY.  [April 

be  obtained  of  any  druggist,  for  five  cents,  to  supply  a 
whole  class. 

1.  Select  from  the  minerals,  collected  by  the  pupils,  a 
number  of  different  kinds,  and  break  off  some  very  small 
pieces  or  splinters  of  each. 

2.  Take  up  one  of  these  with  the  forceps — it  should  not 
be  larger  than  a  pin's  head — and  hold  it  steadily  in  the 
tip   of   the   flame   just  below  the  bright  part.     Does  it 
melt  ?     Look  sharply  at  the  thin  edges  of  the  points  of 
the  piece.     When  melted  thus  it  is  said  to  be  easily  fusible. 
When  minerals   cannot    be  melted,   they   are   infusible. 
Some  minerals,  here  infusible,  might  fuse  in  a  flame  with 
blowpipe. 

3.  In  the  same  way  hold   a  small  lump  of  salt.     Does 
it  melt  ?     What  becomes  of  it  ?     Minerals  which  fly  to 
pieces  when  heated  are  said  to  decrepitate. 

4.  Can    you    detect   any  odor  when    the   mineral   is 
heated  ?     Heat  a  small   piece  of  sulphur  and  note  the 
odor.     Note    the    odor    from    a    small    piece    of    soft 
coal. 

5.  Some  minerals  color  the  flame.     To  get  this  color, 
hold  the  mineral  in  the  edge  of  the  blue  part  of  the 
flame.     The   wick    should   be   new   and  clean   and  the 
alcohol  pure,  so  that  the  flames  may  be  as  nearly  colorless 
as  possible. 

6.  Hold  a  small  piece  of  salt  in  the  flame  ;  what  is  the 
color  ?     This  is  called  the  sodium  flame. 

7.  Try  a  small  piece  of  calcite  in  the  same  way  ;  what 
difference  in  tinge  is  noticeable  ? 

8.  Try  a  piece  of  copper  wire.     What  is  the  color  ? 
Dip  the  wire  into  hydrochloric  acid  and  hold  in  the  flame. 
What  is  the  color  ? 

9.  Take  a  small  piece  of  potassium  chlorate  that  was 


April]  MINERALOGY.  343 

used  in  making  oxygen.     (See  December.)     What  tinge 
has  the  flame  ?     This  is  the  potassium  flame. 

10.  Place    a   very   small    amount    of    the    powdered 
mineral,  not    more   than    half  the  size  of  a  pea,  in  the 
closed  tube  and  heat  gradually  over  the  lamp  ;  watch 
closely  the  sides  of  the  tube.     Are  there  any  drops  of 
moisture  ? 

11.  Try  a  small  amount  of  marble  ,  does  it  undergo 
any  change  ? 

12.  Try   a   little     powdered    gypsum  ;    what    change 
noticed  ? 

13.  Separate  those  minerals  which  contain  water  from 
those  which  do  not  have  it,  as  shown  by  this  test. 

14.  Try  a  little  sulphur  in  the  tube  ;  what  collects  on 
the  sides  of  the  tube  ? 

15.  Use  a  little  powdered  iron  pyrites  ;  note  the  sides 
of  the  tube.     Is  there  any  odor  ? 

16.  The  substance  formed  on  the  sides  of  the  tube  is 
called  a  sublimate.     This  process  is  called  sublimation. 
Compare  with  distillation. 

17.  Repeat    the     experiment,    using    the    open    tube. 
Place  the  mineral  some  distance  within  the  tube  and  hold 
it  but  slightly  inclined,  so  that  the  mineral  will  not  slide 
out. 

18.  Note  the  odor.     Does  sublimation  take  place  as 
before  ? 

19.  Moisten  a  small  slip  of  the  litmus  paper  in  clean 
water  and  hold  in  the  tube  so  that  the  vapors  will  strike 
it.     Which  color  is  affected  ? 

20.  To  get  the   meaning  of  this,  moisten   each  kind 
with  a  little  acid  ;  which  color  is  affected  ?     Try,  in  the 
same  way,  moistening  each  with  a  little  ammonia.     The 
blue  litmus  paper  is  thus  a  test  for  acids,  being  changed 


344  NATURE   STUDY.  [April 

to  red  by  them,  and  the  red  is  a  test  for  alkaline  sub- 
stances, the  color  being  changed  to  blue  by  them. 

21.  Do  all  of  your  minerals  give  off  acid  vapors  ?     Try 
the  above  tests  with  quartz. 

22.  These  exercises  with  minerals  may  be  extended  so 
as  to  include  all  the  specimens  in  their  collections. 


Zoology 

Some  one  has  said  that  the  child  is  a  natural  born  sav- 
age. Whether  this  savagery  is  due  to  inherited  traits 
that  root  far  back  in  his  remote  ancestry,  or  to  a  gross 
ignorance  concerning  the  creatures  about  him,  the  result 
of  criminal  neglect  on  the  part  of  his  teachers,  is  a  ques- 
tion that  will  bear  discussion.  Both  sides  may,  perhaps, 
contain  a  half-truth.  Certain  it  is,  however,  that  as  the 
child  learns  more  and  more  of  the  habits  of  the  living 
things  about  him  he  becomes  less  cruel  in  his  treatment 
of  them.  Cruelty  to  animals  and  their  wanton  destruc- 
tion is  the  concrete,  as  well  as  the  most  pronounced, 
hateful,  and  brainless  expression  of  that  worst  of  all 
traits  of  human  character — selfishness.  The  teacher  of 
natural  science  fails  in  a  most  important  function  of  his 
work  if  the  pupils  that  pass  from  under  his  care  are  not 
ever  afterward  entirely  humane  toward  the  lowly  members 
of  creation.  If  the  teaching  of  elementary  science  in 
the  public  schools  could  accomplish  no  other  end  beyond 
that  of  making  the  children  more  thoughtful,  tender, 
and  considerate  toward  the  brute  creation,  it  would  be 
well  worth  all  the  time  and  attention  its  most  enthusiastic 
advocates  claim  for  it. 

The  robbing  of  birds'  nests  by  the  "  bad  boys  "  of 
every  community  is  a  pastime  that  is  as  common  as  it  is, 
unfortunately,  destructive.  The  natural  timidity  of  the 
birds  is  a  thousandfold  increased,  and  many  a  bush,  tree, 
or  thicket  that  might  become  the  abode  of  a  family  of 

345 


34^  NATURE   STUDY  [May 

feathered  songsters  is  rendered  silent,  tenantless,  and 
dreary  by  the  untimely  raids  of  juvenile  vandals.  It  is 
only  because  the  misgivings,  which  naturally  arise  about 
the  propriety  of  giving  such  directions  in  an  elementary 
work,  are  outweighed  by  the  hope  that  the  teacher's  con- 
stant supervision  and  humane  judgment  will  at  all  times 
prevail  in  properly  directing  the  pupils,  that  instructions 
are  here  given  as  to  the  collection  and  preservation  of 
nests  and  eggs.  Whatever  collections  are  made  by  the 
pupils  should  be  for  the  school  of  which  they  are  mem- 
bers. Taking  nests  and  eggs  for  mere  pastime  or  by 
individuals  who  have  neither  the  means  nor  the  intention 
of  permanently  preserving  them  should  not  be  permitted 
at  all.  The  birds  can  well  afford  to  spare  a  nest  and  a 
set  of  eggs  of  each  kind  for  the  school,  and  in  the  end 
they  will  be  the  gamers  through  the  greater  consideration 
in  treatment  which  they  will  receive  at  the  hands  of  the 
pupils  who  thus  learn  about  them. 

No  nest  or  eggs  should  be  taken  unless  it  is  certainly 
known  to  what  kind  of  bird  they  belong.  Nests  near 
dwellings  and  schools  should  not  under  any  circumstances 
be  disturbed,  as  they  afford  easy  opportunity  for  the 
study  of  the  habits  of  the  birds.  A  nest  should  not  be 
taken  until  it  is  certain  that  the  full  set  of  eggs  has 
been  laid.  To  preserve  a  nest,  remove  it  carefully,  with- 
out displacing  any  of  the  materials,  and  sew  it  through 
and  through  with  a  very  fine  wire.  This  maybe  done  so 
that  the  wire  will  not  be  visible  except  on  very  close  ex- 
amination, and  yet  all  the  parts  will  be  held  firmly  to- 
gether. Do  not  draw  the  wire  tightly  enough  to  change 
the  shape  of  the  nest.  Make  a  stand  as  follows  :  Take  five 
pieces  of  annealed  iron  wire,  about  six  or  eight  inches  long 
and  about  fifteen  gauge.  Twist  them  together  for  three 


May]  ZO&LOGV.  347 

or  four  inches  from  one  end  to  make  a  stem,  and  spread 
the  wires  apart  at  the  other  end  so  as  to  form  in  basket- 
like  support  to  receive  the  nest.  Make  a  hole  of  suit- 
able size  in  a  block  one  inch  thick  and  four  inches  square, 
and  insert  the  end  of  the  stem  formed  by  twisting  the 
wires  as  directed  above.  Put  the  nest  in  position  and 
bend  the  wires  about  it  so  as  to  hold  it  in  place.  Attach 
a  label  bearing  the  name,  date,  location,  and  other  data 
regarding  the  nest.  Nests  thus  mounted  will  bear  a  great 
deal  of  handling  in  class  use. 

To  preserve  the  eggs,  they  must  be  blown.  Break  a 
large  sized  knitting  needle  in  two  in  its  thickest  part  and 
file  the  thick  end  down  to  a  tapering  three-sided  point. 
This  makes  a  serviceable  drill.  Draw  a  small  glass  tube 
to  a  fine  point,  and  at  about  an  inch  from  the  pointed 
end  bend  it  to  nearly  a  right  angle.  In  the  side  of  the 
egg,  drill  a  single  hole,  twirling  the  drill  rapidly  and 
lightly  between  the  thumb  and  forefinger,  the  size  being 
dependent  upon  the  size  and  freshness  of  the  egg. 
Place  the  tip  of  the  blow-pipe  described  above,  at  the 
entrance  of  the  opening  (it  need  not  be  thrust  into  the 
egg),  and,  by  blowing  gently,  the  contents  will  be  forced 
out.  Fill  the  mouth  with  clean  water,  and  by  means  of 
the  blow-pipe  inject  it  into  the  egg  and  thoroughly  rinse 
it  out.  Do  not  wet  or  smear  the  outside,  and  do  not 
wash  off  the  mud  or  any  other  matter  adhering  to  the 
outside  of  the  shell  when  the  egg  was  found.  After 
rinsing  until  the  water  comes  out  clear,  inject,  by  means 
of  a  small  glass  syringe  (a  medicine  dropper  will  do),  a 
little  water  in  which  a  very  little  corrosive  sublimate  (a 
deadly  poison  !  !)  has  been  dissolved.  After  draining 
it  out,  the  eggs  may  be  put  away  in  the  nests  or  trays 
prepared  for  them.  When  the  eggs  contain  embryos,  as 


34^  NATURE  STUDY.  [May 

is  frequently  the  case,  a  large  hole  must  be  drilled  and 
the  contents  be  cut  to  pieces  with  a  pair  of  sharp 
pointed  scissors  and  either  rinsed  out  or  removed  with  a 
hooked  pin. 

If  the  egg  is  large  enough,  with  a  fine  pointed  pen 
write  the  name  of  the  egg  on  the  shell  with  ink  and  also 
number  it.  If  too  small,  then  use  the  number  only.  In 
either  case,  record  the  name  and  number  in  a  check 
book,  and  also  note  the  conditions  under  which  it  was 
found.  A  brief  history  of  the  nest  and  eggs  and  their 
environment  is  interesting,  and  in  the  end  very  valuable. 
Place  the  number  and  name  on  the  same  side  through 
which  the  hole  is  drilled  and  make  it  the  under  side  as 
the  egg  lies  in  the  tray. 

BIRDS'  NESTS   AND   EGGS. 

1.  Make  a  study  of  the  materials  found  in  different 
birds'  nests;. what  points  of  similarity  and  contrast  do 
you  find  between  those  that  build  on  the  ground  and  those 
that  build  in  trees  ? 

2.  Which  class  of  birds  build  the  more  elaborate  nests, 
the  ground  or  arboreal  ? 

3.  Where  are  the  materials  for  the  ground  nests  ob- 
tained ?    What  objects  does  the  bird  appear  to  have  in 
view  in  selecting  a  site  ? 

4.  Are  the  materials  uniformly  of    the  same  kind  in 
the  arboreal  nests  ? 

5.  By  what  devices  are  different  nests  held  in  place  ? 
Are  they  the  same  in  nests  of  the  same  kind  of  bird  in 
different  places  ? 

6.  Where  is  the    material  obtained  ?      Do    the    birds 
prepare  it  in  any  way  before  building  it  into  the  nest  ? 


May]  ZOOLOGY.  349 

7.  How  do  they  carry  the  materials  ?     Do  both  sexes 
engage  in  the  work  ? 

8.  Note  and  compare  the  different  locations  selected. 
Can  you  see  the  advantages  of  each  ? 

9.  Do  the  birds  display  intelligence  in  building  their 
nests,  or  can  you  account  for  all  you  see  through  inherited 
instinct  ?     What  would  be  a  fair  test  as  to  whether  blind 
instinct  or  intelligence  guides  the  bird  ? 

10.  Can  you  find  any  odd  or  new  adaptations  to  the 
surrounding  conditions  in  any  of  the  nests  ? 

11.  What  are  the  devices  for  concealment,  natural  and 
artificial  ? 

12.  Is  there  any  correspondence  between  the  color  of 
the  bird  and  the  character  of  the  nest  ? 

13.  Compare  the  nests  of  the  brightly  colored  birds  with 
those  that  are  dull  colored.     Is  there  any  attempt  made 
to  simulate  the  surroundings  in  any  way  ? 

14.  At  what  time  in  the  day  are  the  eggs  laid  ?     Aawhat 
intervals  ? 

15.  Can  you  see  any  reason  for  the  coloring  and  pecu- 
liar marking  of  some  of  the  eggs  ?    Can  you  see  why  some 
eggs  are  pure  white  ? 

1 6.  Is  the  number  of  eggs  laid  uniform  with  the  same 
kinds  of  birds  ? 

17.  Note  the  time  when  the  female  begins  to  sit  ;  what 
does  the  male  do  during  this  period? 

1 8.  How  long  before  the  young  birds  appear?     Note 
the  date. 

PARTS   OF   AN   EGG,   AND   THE    EMBRYO. 

(Use  a  hen's  egg.} 

Some  teachers  will  have  opportunity  at  this  point  to 
suggest  and  conduct  a  series  of  most  interesting  observa- 


35°  NATURE    STUDY.  [May 

tions  on  the  incubation  of  the  hen's  egg.  Among  the 
pupils  there  will  doubtless  be  some  who  are  the  owners 
of  a  flock  of  chickens.  If  so,  it  is  not  difficult  to  find 
one  or  more  hens  that  are  willing  to  do  their  part  of  the 
experiment  by  sitting  upon  a  nest  of  eggs.  Start  with 
about  twelve  eggs  in  the  nest  and  replace  those  taken  out 
until  the  total  number  reaches  twenty-one  or  twenty-two. 
Mark  each  new  egg  put  into  the  nest  with  the  date  so  that 
they  may  be  removed  in  proper  succession.  When  the 
egg  is  removed,  always  keep  that  side  uppermost  which 
was  so  in  the  nest.  With  a  knife  point  or  pin  puncture 
the  large  end.  Can  you  see  why  this  is  done  ?  Then 
tap  lightly  on  the  upper  side  of  the  shell  until  enough  is 
broken  to  make,  when  it  is  removed,  a  hole  about  the 
size  of  a  penny.  Carefully  remove  the  membranes,  and 
look  for  any  changes  that  may  have  taken  place  within. 
If  a  compound  microscope  be  at  hand,  there  may  be  seen, 
within  a  few  hours,  most  wonderful  evidence  of  a  new  life 
that  has  just  begun.  (See  Zoology  for  March.)  Even 
to  the  unaided  eye  the  changes  are  very  soon  well 
marked.  Examine  an  egg  every  twenty-four  hours,  and 
note  the  progress  of  development.  It  is  well  to  remove 
the  embryo  chick  and  preserve  the  series  for  further 
study.  To  do  this,  immerse  the  egg,  the  opening  upper- 
most, in  a  vessel  of  strong  salt  water.  With  fine-pointed 
scissors  cut  around  the  area,  plainly  visible,  occupied  by 
the  embryo  chick  and  let  it  float  out  of  the  shell.  Catch 
it  on  a  bit  of  cork  or  smooth  soft  wood  and  keep  it 
spread  with  pins.  Sink  this  in  weak  alcohol.  As  the 
development  proceeds,  less  trouble  will  be  experienced 
in  removing  the  embryo.  Small  wide-mouthed  ointment 
bottles  are  excellent  receptacles  in  which  to  preserve  the 
specimens.  Each  bottle  should  have  a  label  bearing  the 


May]  ZOOLOGY.  351 

date   when    the  embryo   was   removed   and   its    age   in 
days. 

1.  Note    the    general    shape   and    size  ;  what    is    the 
ratio    of  the  length  to  the  breadth  ? 

2.  Carefully  remove  the  shell  from  one  side  ;  how  many 
linings  inside  of  it  ? 

3.  Note  the  clear  white  called  the  albumen.     Also  the 
yellowish  center,  called  the  yelk. 

4.  Observe  the  small  white  spot  on  the  upper  side.    This 
is  called  the  germinal  spot.     Observe  this  spot  when  the 
process  of  hatching  begins.    Did  you  ever  see  it  anywhere 
except   on   top  of  the  egg?     What  advantage  in  this  ? 

5.  Remove  the   shell  from  a  hard  boiled  egg  ;  do  the 
contents  entirely  fill  the  shell  ?     What  reason  can  you  as- 
sign ? 

6.  What  is  the  very  first  evidence  of  life  in  the  egg  ? 
In  what  length  of  time  did  it  appear  ? 

7.  Can    you    find    any    evidence    of  internal   organs  ? 
What  ones  appear  to  be  the  most  necessary  ? 

8.  Which  appears  first,  the  outline  of  the  body,  the 
skeleton,  or  the  internal  organs  ? 

9.  Where  does  the  nourishment  necessary  for  growth 
come  from  ?     Does  the  embryo  chick  eat  ?     How  does  it 
get  its  food  ?     Does  it  need  air  ?     Does  it  breathe  ? 

10.  How   soon   can   you   notice  the  formation  of  any 
external  organs  ?     What  are  they  ?     Which  part  of  the 
body  is  most  conspicuous  ? 

u.  Notice  very  carefully  the  first  appearance  of  the 
legs  and  wings  ;  can  you  observe  any  differences  ? 

12.  How  soon  do  bodily  movements  begin  ? 

13.  When  do  feathers  first  appear?     In  what  parts  of 
the  body  are  they  found  ?     How  are  they  arranged  ? 

14.  What  becomes  of  the  contents  of  the  shell  ? 


35 2  NATURE   STUDY,  [May 

15.  Why  is  it  that  the  chick  has  no  use  for  its  beak 
while  developing  in  the  shell  ?     Does  it  use  its  stomach  ? 
Why? 

16.  What  is  the  first  use  it  makes  of  its  beak  ? 

17.  After  what  length  of  time  does  it  leave  the  shell  of 
its  own  accord  ? 

1 8.  What  changes   take  place   in  its   mode  of  living 
when  it  leaves  the  shell  ? 

19.  Compare  its  feathers  with    those   of  the  mature 
bird  ;  do  the  feathers  themselves  change  ? 

20.  Compare    the     new-born    chick    with    new-born 
animals  of  other  kinds  in  vigor,  intelligence,  and  self- 
dependence. 

THE    CRAWFISH. 

1.  Collect  some  crawfish  and  place  them  in  an  aquarium 
or  jar  of  water  for  daily  observation. 

2.  Note  the  character  of  the  places  whcrj  they   are 
found  ;  is  the  water  clear  or  muddy,  still  or  running  ? 

3.  How  many  ways  have  they  of  moving.      Contrast 
these  ways.     Study  the  flexible  part  of  the  body  ;  it  is 
called  the  abdomen.    Make  a  drawing  of  it. 

4.  What  is  the  chief  means  of  propulsion  in  swimming  ? 
Compare  the  parts  and  form  of  the  tail-fin  during  the 
stroke  with  that  during  the  return.     By  what  contrivances 
is  the  resistance  reduced  during  the  latter  movement  ? 

5.  Do  the  legs  perform  any    function   in    swimming  ? 
What  is  their  position  when  it  swims  ? 

6.  Study  how  the  animal  walks  ;  are  all  the  limbs  used 
in  performing  this  movement  ? 

7.  Can  you  see  the  use  of  the  short  limbs  under  the 
hinder  part  of  the  body  ?     These  are  called  swimmer ets. 

8.  Can  the  animal  see  where  he  is  going  when  swimming 
tail  foremost  ?     What   peculiarity  do   you  notice  about 


May]  ZOOLOGY.  353 

the  eyes  ?    Examine  the  eye  under  a  lens  ?     Is  it  sensitive 
to  the  touch  ? 

9.  By  what  means  does  he  move  his  eyes  ? 

10.  What    is  the    food  of   the  crawfish  ?     How   does 
he   seize   it  ? 

n.  How  do  his  prehensile  organs   differ  from  those 
used  most  in  walking  ? 

12.  What  advantage  do  you  see  in  the  great  number 
of  joints  ?     How  do  we  manage  to  execute  even  a  greater 
variety  of  movements  with  fewer  joints  ? 

13.  Note  the  different  parts  concerned  in  bringing  the 
food  to  his  jaws.     Is  the  food  cut,  crushed,  or  ground  by 
the  jaws  ?     What  can  you  see  of  the  movements  ? 

14.  How  does  the  crawfish  breathe  ?     Does  it  come  to 
the  surface  of  the  water  for  air  ? 

15.  Lift  slightly  the  shell-like  covering  of  the  forward 
end  of  the  body  by  taking  hold  of  its  edges  ;  note  the 
little  brush-like  gills  lying  close  to  the  side  of  the  body. 

16.  Can  you  discover  the  means  by  which  fresh  water 
is  continually  furnished  to  the  gills  ?     Put  the  animal  in- 
to a  shallow  pan  of  water  and  watch  carefully  with  this 
in  view. 

17.  Which  way  does  the  current  of  water  flow  ? 

1 8.  Can  the  crawfish  live  when  removed  from  the  water  ? 
Why  is  this  ?     Why  can  we  not  live  long  if  placed  under 
water  ? 

19.  Has  the  crawfish  the  sense  of  touch  ?     By  using 
a  pencil  or  any  other  means  find  the  organs  of  feeling. 

20.  Has  it  the  sense  of  hearing  ?     Do  not  try  to  answer 
this  question  until  you  have  made  a  proper  test.     In- 
vent some  way  by  which  a  test  may  be  applied.     Can 
you  locate  his  ears  ? 

21.  Try  to  find  a  crawfish  with  eggs  or  young  ones  at- 


354  NATURE   STUDY.  [May 

tached.     Tf  one  with  the  eggs  be  found,  note  the  move- 
ments of  the  swimmerets.     Why  is  this  ? 

22.  How  does  a  crawfish  fight  or  defend  himself  ?     If 
any  should  have  a  limb  torn   off  in  combat,  put   it  in   a 
small  tank  by  itself  and  observe  what  takes  place  in  a  few 
weeks. 

23.  How  is  it  possible  for  a  crawfish  to  grow,  since  the 
stiff,  hard  covering  is  on  the  outside  of  the  body  ?     Have 
you  any  proof  that  the  shell  is  shed  sometimes  ? 

24.  How  many  distinct  things  are  done  by  the  various 
appendages  of  the  crawfish  ?     How  many  are  devoted  to 
each  particular  kind  of  work  ? 

25.  The  following  synopsis  of  the  external  characters 
is  appended  to  assist  the  teacher  : 

Cephalothorax  ;  the  anterior  inflexible  part  of  the 
body.  Note  its  covering,  the  carapace,  and  its  pro- 
jecting spine  in  front,  the  rostrum. 

Abdomen  ;  posterior  flexible  part  of  the  body. 

Eye-stalks  ;  appendages  carrying  the  eyes. 

Antennules  ;  pair  of  small  feelers. 

Antennae  ;  pair  of  large  feelers. 

Mandibles  ;  jaws. 

Maxillae  ;  two  pairs  next  behind  mandibles. 

Maxillipedes  ;  three  pairs  next  behind  maxillae. 

Great  chelae  ;  largest  claws,  one  pair. 

Legs  ;  remaining  pairs  on  the  cepbalothorax. 

Swimmerets  ;  abdominal  appendages. 

Telson  ;  middle  piece  of  tail  fin.  Compare  it  with 
the  other  abdominal  segments. 

SEEING. 

i.  Try  reading  from  a  book,  standing  in  the  follow- 
ing different  positions  :  Facing  the  light,  with  the  back 


May]  ZOOLOGY.  355 

to  it,  and  with  it  at  one  side.  Which  enables  ycu  to  see 
most  clearly  ?  Try  to  give  a  reason.  (Recall  lessons  in 
Physics  for  March.) 

2.  Try  to  read  holding  the  book  at  different  distances 
from  the  eye  ;  what  is  the  best  distance  for  you  ?     If  you 
are  compelled  to  hold  this  book  at  much  less  than  fifteen 
inches  you  are  probably  near-sighted. 

3.  Can  you  see  near  and  distant  objects  distinctly  at 
the  same  time  ?     Look  at  the  window  sash  and  then  at  some 
object  beyond.     Can  you  account  for  the  fact  that  a  little 
time  intervenes  before  the  latter  becomes  distinct  ?     Why 
is  it  bad  for  the  eyes  to  read  while  on  a  vehicle  in  mo- 
tion ? 

4.  What  is  the  effect  on  one's  vision  to  pass  from  a  light 
room  to  a  dark  one  ?     From  a  dark  one  to  a  light  one  ? 
To  understand  this,  stand  facing  a  strong  light.     Hold  a 
mirror  to  one  side  toward  a  dark  wall  or  surface.     Sud- 
denly turn  and  look  into   the  mirror  ;  watch    narrowly 
the  small  black  opening  in  the  eye  called  the /#///.     How 
does  it  change  ? 

5.  Turn  quickly  toward  the  light  and  hold  the  mirror 
in  front ;  what  change  is  noticed  ?     The  curtain  which 
by  contracting  and  relaxing  alters  the  size  of  the  pupil, 
is  the  iris.     Note  its  color. 

6.  Watch  the  changes  of  the  pupil  in  a  cat's  eye  and 
compare  with  your  own.    Observe  the  pupil  in  an  owl's  eye. 
Can  you  see  a  reason  for  its  great  size  ? 

7.  Can  you  give  a  reason,  from  what  you  have  seen, 
why  one  should  have  a  steady  light  and  not  a  flickering 
one  ?    What  precaution  would  you  suggest  when  going  from 
a  dark  room  to  a  brilliantly  lighted  one  ? 

8.  Why  are  objects  less  distinct  at  first  when  there  is  a 
sudden  change  in  the  intensity  of  the  light  ? 


356  NATURE   STUDY.  [May 

9.  Of  what  use  are  the  eyebrows  ?     Of  the  eyelashes  ? 

10.  Why  do  not  the  eyelashes  interlock  when  we  wink  ? 
Can  you  see  a  good  reason  for  winking?     Can  you  stop 
winking  if  you  so  will  it  ? 

n.  Examine  a  cat's  eye  when  she  winks.  Close  it 
quietly  with  the  hand  and  allow  it  to  open  slowly  ;  do  you 
notice  anything  different  from  your  own  eye  ?  Examine 
your  eye  carefully. 

12.  Examine  the  eyes  of  other  animals  for  the  same 
thing  ;  the  dog,  the  frog,  the  bird,  the  turtle,  for  example. 

13.  Can  you  see  why  we  shed  tears  when  a  cinder  gets 
into  the  eye  ?     Why  do  we  do  it  when  hurt  severely  in  any 
part  of  the  body  ?     Why,  when  we  feel  extremely  sad  ? 

14.  What  becomes   of  the  moisture  in  the  eyes  under 
ordinary  circumstances  ?     Standing  before  a  mirror,  pull 
the  lower  lids  out  slightly  and  look  for  a  hole  on  the  small 
elevation  at  the  inner  end  ;  this  is  the  opening  into  a  tube 
which  leads  to  the  nose.     Can  you  find  a  similar  opening 
in  the  upper  lid  ?     Through  this  tube  the  water  is  drained 
off  as  fast  as  secreted  under  usual  conditions.     The  tear 
gland  is  situated  above  the  eyeball,  about  midway  between 
the  outer  angle  of  the  eye  and  the  middle  of  the  bony  arch. 

15.  Note  the  thickened  but  flexible  edges  of  the  lids  ; 
they  are  kept  smooth  by  oil,  which  is  poured  out  at  the 
roots  of  the  lashes.     Sometimes  this  is  in  such  quantities 
that  the  eyes  are  glued  together  in  the  morning  ;  if  so, 
slightly  moisten  the  edges  with  saliva.     To  prevent  this, 
wash  the  eyes  well  with  warm  water,  and  then  bathe  freely 
with  cold  water  before  retiring.     Use  them  less  at  night. 


Botany 

May  is  a  month  of  flowers.  At  no  season  of  the  year 
do  they  seem  so  beautiful  and  so  fresh  as  now.  Where 
a  few  weeks  ago  there  was  naught  but  the  bare  earth  or 
brown  leaves,  the  relics  of  a  past  season,  the  magic  of  the 
sunshine  has  now  brought  forth  the  delicate  blossoms  as 
the  harbingers  of  a  new  life.  Botany,  in  the  past,  has 
meant  largely  a  rending  to  pieces  of  these  flowers  in  an 
endeavor  to  find  their  name  by  means  of  an  artificially  ar- 
ranged key.  The  key  has  its  place  and  is  useful,  but  it  is 
not  designed  for  children  or  beginners  of  any  age.  It  is 
not  likely  to  lead  to  an  intelligent  study  of  plant  life.  To 
secure  this,  much  attention  should  be  given  to  the  habits 
of  plants — for  plants  as  well  as  animals  have  habits,  one 
is  tempted  to  say,  likes  and  dislikes — and  it  is  through 
these  that  easy  entrance  is  made  to  the  study.  The  flower, 
however,  is  but  one  part  of  a  plant,  and  its  study  should 
not  be  separated  from  the  study  of  the  plant  as  a  whole. 

Since  children  are  so  universally  attracted  by  flowers 
almost  from  the  dawn  of  existence,  it  is  frequently  a 
matter  of  great  astonishment  to  teachers  to  find  how  dull 
a  subject  the  study  of  the  flower  sometimes  becomes  to 
their  pupils.  It  must  ever  be  kept  in  mind  that  children 
are  most  deeply  interested  in  objects  through  their  func- 
tions. Now  the  only  function  which  the  child  can  see 
for  the  flower  is  to  make  woodland  and  meadow  beautiful 
for  his  own  pleasure  ;  and  since  it  can  perform  this  func- 
tion only  in  its  entirety,  he  cannot  be  expected  to  en- 

357 


35 8  NATURE   STUDY.  [May 

thusiastically  pick  it  to  pieces  for  the  purpose  of  study. 
Whether  the  flower  has  five  petals  or  ten  stamens  or  a 
compound  pistil  is  a  matter  of  no  consequence  to  him 
whatever  ;  and  in  the  early  stages  of  observation,  there- 
fore, he  should  not  be  troubled  with  such  things.  But 
instead,  let  him  gather  as  many  as  possible,  and  drink  in 
their  separate  and  combined  beauties,  and  then  project 
the  treasures  of  his  soul,  by  means  of  brush  and  pencil, 
until  his  firm  and  loving  companionship  with  them  is 
fully  established.  It  is  this  growing  bond  of  union  be- 
tween child  and  flower,  alone,  which  can  later  lead  to 
deeper  study  that  is  honest  in  its  purpose,  intelligent  in 
its  character,  and  fruitful  in  its  results. 

The  classes  should  in  all  cases,  where  practicable,  visit 
the  flowers  in  their  native  haunts.  The  younger  pupils 
may  gather  all  within  their  reach  and  the. more  advanced 
may  be  limited  more  or  less  to  those  of  a  particular  kind 
or  to  those  growing  in  a  certain  prescribed  area  of  pecu- 
liar conditions.  In  all  cases  attention  should  be  directed 
to  the  relation  of  the  surroundings  to  the  plant  and  its 
adaptation  to  its  environment. 

1.  Why  is  it  that  some  plants  can  blossom  so  early  in 
the  season  and  others  must  wait  until  fall  ?     In  trying  to 
answer  this,  examine,  if  possible,  such  plants  as  Spring 
Beauty,  Hepatica   or    Liver-leaf,   Dutchman's  Breeches, 
Bloodroot,  Dentaria  or  Toothwort,  and  Trillium. 

2.  Have  any  of  the  seeds  which  you  planted  last  month 
produced  flowers  ? 

3.  Have  any  of  the  flowering  plants  mentioned  above 
come  from  the  seed  this  spring  ? 

4.  What  advantage  do  such  plants  have  over  others  in 
the  spring  ? 

5.  What  differences  have  you  observed  among  those 


May]  BOTANY.  359 

mentioned  in  (i)  ?  Compare  the  Hepatica  with  the 
Spring  Beauty. 

6.  Do  you  find  them  growing  in  exactly  the  same 
locations  ? 

V.  What  appears  to  be  the  favorite  place  of  the 
Hepatica  ?  Of  the  Spring  Beauty  ? 

8.  Do  you  find  one  growing  in  any  location  where  the 
other  is  not  to  be  found  ?     Examine  wet,  dry,  cool,  warm, 
wooded,  and  open  places  ? 

9.  In  what  respects  is  the  Hepatica  adapted  to  wood- 
land ?     Is  it  equally  well  adapted  to  open  places  ?     Why  ? 

TO.  Can  you  see  why  the  Hepatica  can  bloom  even 
earlier  than  the  Spring  Beauty  ? 

1 1.  What  do  the  early  flowering  plants  do  the  remainder 
of  the  season  ? 

12.  How  many  different  arrangements  of  the  flowers 
on  the  plants  have  you  observed  ?     The  arrangement  of 
the  flowers  is  called  the  inflorescence  of  the  plant. 

13.  Compare  the  inflorescence  of  the  plants  mentioned 
above    in  (i)  ;  which    ones   are  clustered?     Which  are 
single  ?     The  latter  are  said  to  have  solitary  inflorescence. 

14.  Where    are   the   oldest  flowers    in    the   clusters  ? 
The  youngest  ?     When  the  flowers  open  from  the  outside 
of  the  cluster  inward  or  from  below  upward,  the  inflor- 
escence is  centripetal  or  indeterminate.     When  the  reverse 
is  true  it  is  centrifugal  or  determinate. 

15.  What  is  the  most  common  color  of  flowers  that  you 
find  ?     Which  color  is  least  common  ?     Can  you  see  any 
reason  for  this  ? 

16.  Can  you   see  any  advantage  to   the  plant  in  the 
color  of  its  flowers  ?     Do  the  flowers  remain  open  day 
and  night  ?     Are  there  any  that  bloom  only  at  night  ? 
Are  there  any  that  bloom  only  during  the  day  ? 


36°  NATURE    STUDY.  [May 

17.  Can  you  find  any  that  bloom  for  a  day  only  ? 

1 8.  Do  any  of  the  flowers  that  you  have  found  have 
odor  ?     Where  is  this  located  ? 

19.  Why  do  the  bee  and  other  insects  visit  flowers? 
Where  are  the  sweets  (nectar)  stowed  away  ?     To  answer 
this,  watch  an  insect  very  closely  and  taste  the  different 
parts  of  the  flower.     Where  does  the  odor  come  from  ? 

20.  How  does  the  insect  know  where  to  look  ? 

21.  Why  is  it  that  the  flower  so  kindly  feeds  the  insect? 

22.  Do  the  insects  carry  away  anything  besides  nectar 
from  the  flower  ?     How  do  they  get  it  ? 

23.  How  many  different  sets  of  parts  do  you  find  to  a 
flower,  the  Spring  Beauty,  for  example  ? 

24.  Each  set  is  called  a  whorl,  even  though  it  consists 
of  but  a  single  part.     In  the  Spring  Beauty,  for  instance, 
is  the  single  central  part  called  the  pistil.     Surrounding 
this  is  a  whorl  or  circle  of  stamens ;  next  outside  is  the 
delicately  colored  corolla,  and  still  outside  of  all  is  the 
calyx. 

25.  Are  there  four  whorls  present  in  all  the  flowers  that 
you  have  found  ?     Which  whorls  have  you  found  absent  ? 
When  any  one  or  more  of  the  whorls  is  absent,  the  flower 
is  incomplete.     When  all  are  present  it  is  complete. 

26.  Can   you    see   any   use   for   the   pistil?    Note  its 
enlarged    basal    part    called    the   ovary;   what    does    it 
contain  ?     The  undeveloped  young  seeds  are  called  ovules. 

27.  Note  the  slender  stalk  on  top  of  the  ovary  called 
the  style  and  the  three-lobed  tip  called  the  stigma.     Is 
there  any  evidence  of  a  whorl  of  parts  united  in  the  pistil 
of  the  Spring  Beauty? 

28.  Examine    the    stigmas    of   different    flowers    very 
carefully  ;  do  you  find  anything  adhering  to  them  ?     Use 
a  magnifier. 


May]  BOTANY.  36r 

29.  Shake   a   flower   over   a   clean     piece    of    paper  ; 
where  does  the  dust  come  from  ?     The  stamens  have  two 
parts,  usually,  the  slender  filament  and  the  enlarged  knob- 
like  anther.     The  yellowish  powder  from  the  anther  is  the 
pollen. 

30.  The  parts  of  the  corolla  are  called  petals.     Are  they 
present  in  all  flowers  that  you  have  seen  ?     Of  what  use 
to  the  flower  is  the  corolla  ? 

31.  The  calyx,  as  seen  in  the  Spring  Beauty,  is  com- 
posed of  parts  called  sepals.     What  appears  to  be  their 
use? 

32.  The   stamens   and    pistil  together  are   called  the 
essential  organs  of  the  flower.    Can  you  see  why  the  pistil 
should  be  classed  as  an  essential  organ  ? 

33.  Taken  together,  the  corolla  and  calyx  are  called  the 
perianth.     When  the  perianth  consists  of  colored  parts 
only,  it  is  usually  the  calyx.     The  whorls  of  the  perianth 
are  sometimes  called  the  floral  envelopes.     Why  ? 

34.  Note  the  whorl  of  green  leaves  just  at  the  base  of 
the  flower  in  the  Hepatica.     Is  it  a  calyx  ?    Compare  with 
the  Spring  Beauty. 

35.  Note  the  position  of  the  flowers  on  different  plants. 
Can  you  understand  why  some  droop  while  others  are 
upright  ?     Does  the  position  seem  to  affect  the  growth  of 
any  of  the  whorls  ? 

36.  Compare    the    stamens    and    pistil    in    drooping 
flowers  with  those  habitually  erect.     Can  you  find  any 
prevailing  contrast  ? 

37.  Compare  these  with  flowers  that  project  sidewise 
from  the  stem  ?     Is  there  any  constant  difference  in  the 
shapes  of  flowers  that  grow  in  different  positions  ?     Can 
you  see  any  reason  for  it  ? 

38.  Flowers  in  which  the  different  parts  of  the  same 


3^2  NATURE   STUDY.  [May 

whorl  are  not  of  the  same  size  or  shape  are  said  to  be 
irregular.  Can  you  see  anything  in  the  growth  of  the 
plant  which  would  tend  to  produce  irregular  flowers  ? 

39.  Carefully  compare  the  number  of  parts  in  the  dif- 
ferent whorls  of  the  flowers  ;  where  there  is  not  the  same 
number  of    parts  in   each  whorl,  the  flower  is   unsym- 
metrical. 

40.  Can  you  find  any  ruling  number  in  the  parts  of 
the  flower?    What  is  the  most  common  number?     The 
next  prevailing  number  ? 

41.  How  are   the   parts   of  one  whorl  arranged  with 
respect  to  the  adjacent  whorls  ?     Are  all  flowers  alike  in 
this  particular  ? 

42.  Are  the  petals  separate  in  all  the  flowers  you  have 
examined  ?     When  separate,  they  are  said  to  be  distinct 
and  the  corolla  is  polypetalous.     When  united  entirely  or 
in  part  they  are  said  to  cohere,  and  the  corolla  \$gamopctal- 
ous. 

43.  Note   in   the    same   way   the   calyx  ;  it   is   either 
polysepalous  (distinct  sepals)  or  gamosepalous  (cohering 
sepals). 

44.  Can  you  find  a  flower  when  one  whorl  grows  fast  to 
another?     It  is  then  said  to  be  adnate.     Examine  apple 
or  cherry  blossoms. 

BUDS. 

1.  Procure  a  branch  on  which  the  buds  are  unfolding. 
Do  all  of  its  parts  develop  into  leaves  ? 

2.  What  do  you  find  inside  the  bud  ?     Cut  one  of  the 
buds  lengthwise  and  another  crosswise  and  examine  the 
arrangement    of   the    parts   inside.     Make   drawings   to 
show  it. 

3.  Are  the  small  leaves  all  packed  away  in  the  bud 


May]  BOTANY.  363 

in  the  same  manner  ?  Pick  a  bud  to  pieces  and  notice 
how  each  leaf  is  wrapped  or  folded.  The  folding  of  the 
leaf  in  the  bud  is  called  the  vernation  of  the  leaf.  Is 
there  any  relation  noticeable  between  the  shape  of  a  leaf 
and  its  vernation  ? 

4.  As  the  young  branch  grows,  can  you  see  any  indica- 
tions of  new  buds  being  formed  on  it  ?     In  what  positions 
do  they  grow  ? 

5.  Is  there  any  growth  in  the  last  year's  branch  which 
is  now  putting  forth  the  new  ones  ? 

6.  What  is  the  difference  in  the  texture  and  general 
appearance  between  the  new  and  the  old  branches  ? 

7.  On    some    rapidly    growing    branch     make    some 
measurements  and  determine  the  daily  rate  of  growth. 
A   lilac,  poplar,  or  willow  will  be   a   good    one   to   ob- 
serve. 

8.  Can  you  tell  where  the  new  material  is  deposited 
which  elongates  the  branch  ? 

9.  Watch  closely  the  time  when  the  twigs  on  the  tree 
selected  for  study  in  the  spring  stop  growing  ;  has  the 
tree  any  work  to  do  during  the  remainder  of  the  season 
after  the  growth  of  the  twig  stops? 

10.  On  what  part  of  the  tree  are  the  strongest  growths 
produced  ?     Can  you  give  a  reason  for  it  ? 

FERNS. 

For  beauty  and  gracefulness  of  appearance  the  ferns 
rival  any  of  the  flowering  plants.  The  field  lesson  will 
reveal  the  fact  that  they  are  as  attractive  to  the  pupils  as 
any  of  their  more  pretentious  neighbors,  and  they  should, 
therefore,  receive  their  share  of  attention. 

i.  Can  you  find  anything  about  the  fern  that  resem- 
bles a  flower  ? 


3<$4  NATURE   STUDY.  [May 

2.  Does   it  produce  a  stem  as  other  plants  do  ?     Ex- 
amine the  part  under  ground. 

3.  In  what  locations  are  ferns   to  be  found  ?     Do  they 
seem  to  have  anything  in  common  with  other  plants  in 
the  same  location  ? 

4.  Notice  the    small  brown  dots  called  sort  (singular 
sorus)   on  the  back  of    the   fern-leaf   or   frond.       Such 
fronds  are  called  fertile,  for  it  is  from  the  fine  dust-like 
spores  that  come  from  the  sori  that  the  young  ferns  are 
produced.     These  are  much  too  small  to  be  studied  with 
the  unaided  eye. 

5.  Are  all  the  fronds  fertile  ?     Can  you  find  any  ferns 
that  do  not  produce  the  sori  on  the  back  of  the  fronds  ? 
Are  they  all  arranged  the  same  way  when  they  do  grow 
on  the  back  of  the  fronds  ? 

MOSSES. 

1.  In  what  locations  do  you  find  mosses  most  abun- 
dant?    How  do  the  locations  differ  from  those  of  most 
plants  ? 

2.  Do  you  find  them  growing  in  dry  as  well  as  moist 
spots  ? 

3.  Does  the  moss  found  growing  upon  the  trunk  of  a 
tree  derive  its  nourishment  from  the  tree  ? 

4.  Do  those  which  grow   upon  rocks,  use  the  rock  as 
other  plants  use  the  soil  ? 

5.  Do  mosses  have  roots  ?     Do  they  have  flowers  ? 

6.  Can  you  find  any  moss  that   is   sending  up  delicate, 
thread-like  stems  sailed  seta,  which    bear  small  spore- 
cases   on    top  ?     The  lid-like   covering  of   the  latter  is 
called  the  calyptra. 

7.  Remove  the   calyptra   and  shake   the  moss  over  a 
clean  sheet  of  paper.  These  minute  dust-like  bodies  are 


May]  BOTANY.  365 

called  spores,  and  from  these   the  young  plant  is  pro- 
duced. 

8.  Do  you  find  any  resemblance  in  the  mosses  to  the 
ferns  ?  To  flowering  plants  ?  What  are  the  chief  differ- 
ences from  the  latter  ? 


SOUND. 

In  the  study  of  sound  there  are  many  interesting 
experiments  which  may  be  performed  that  will  properly 
open  up  the  subject  for  young  beginners  and  lead  them 
to  further  observation.  Experiments  may  be  per- 
formed by  the  pupils  which  will  enable  them  to  see 
something  of  the  relation  of  sound  to  vibrating  bodies  ; 
but  it  is  not  so  easy  to  devise  those  which  will  show 
directly  that  air  is  a  conducting  medium  ;  nor  is  it  possible, 
by  actual  experiment,  for  them  to  understand  very  clearly 
the  nature  of  the  sound  waves  in  it. 

Initial  interest  in  the  subject  may  be  gained  by  taking 
up  some  sounds  with  which  the  pupils  are  familiar.  Noth- 
ing will  more  certainly  assure  this  than  some  simple  in- 
strument, such  as  an  yEolian  harp,  which  may  be  con- 
structed by  the  pupils  as  follows  :  Take  a  dry  pine  board, 
about  six  or  eight  inches  wide  by  one-half  inch  in  thick- 
ness, and  cut  it  so  that  it  will  slip  easily  into  the  window 
when  the  sash  is  raised.  Drive  about  ten  tacks  or  small 
nails  in  each  end,  opposite  each  other,  letting  the  heads 
project  about  one-eighth  of  an  inch.  If  small  screw  eyes 
instead  of  nails  are  used  in  one  end,  the  strings  may  be 
keyed  up  or  loosened  as  desired.  Beginning  at  one  side 
stretch  from  the  first  nail  in  one  end  to  the  one  opposite 
it  in  the  other  a  single  silk  thread,  which  has  been  well 

366 


May]  PHYSICS.  367 

waxed.  Then  twist  two  threads  together  tightly  and  wax 
them  and  stretch  between  the  second  pair  of  nails,  and  so 
on  increasing  each  cord  by  one  thread  of  silk.  Next, 
make  two  bridges  of  hard  wood  of  the  same  size  and 
shape.  Their  length  should  equal  the  width  of  the  board, 
and  they  should  be  about  one  and  one-half  inches  wide 
at  one  end  and  three-quarters  of  an  inch  at  the  other. 
The  upper  edge  which  supports  the  strings  should  be 
beveled  to  a  sharp  edge.  Slide  the  bridges  on  their 
sides  under  the  strings  near  the  middle  of  the  board 
and  then  turn  them  up  properly  and  slip  them  along 
toward  either  end  of  the  board  until  the  strings  are  all 
quite  taut.  Raise  the  sash  high  enough  to  clear  the 
bridges  and  place  the  board  in  the  window.  A  very 
slight  breeze  will  start  the  music,  which  will  continue  to 
be  produced  while  the  wind  blows,  with  almost  infinite 
variation. 

1.  What  is  the  cause  of  the  sound  that  comes  from 
the  ^Eolian  harp  ? 

2.  Can  you  discover  how  it  is  produced  ?     Fold  a  few 
very  light,  narrow  strips  of  paper  half  an  inch  long,  and 
drop  them  across  the  middle  of  different  strings  ;  what 
do  you  notice  when  the  wind  blows  across  the  string  ? 

3.  Lay  a  small  stick  of  wood  across  the  middle  of  the 
strings  ;  what  effect  does  it  have  upon  the  music  ? 

4.  How  are  the  low  tones  produced  ?     Place  a  stick 
upon  different  sets  of  the  strings  and  note  the  result. 

5.  What  produces  the   high    tones  ?     What   is    there 
about  the  strings  of  the  harp  which  affects  the  pitch  ^f 
the  tone  ? 

6.  What    causes  the  loud    tones  ?     Do  loudness  and 
pitch  depend  upon  the  same  thing  ? 

7.  Why  is  it  that  sometimes  very  soft  tones  are  pro- 


368  NATURE   STUDY.  [May 

duced  ?     Are  all  the  strings  capable  of  producing  soft 
tones  ?     Test,  as  before,  with  a  stick. 

8.  What  is  the  difference  between  a  low  tone  and  a 
soft  tone  ? 

9.  Compare  a  loud  tone  with  a  high  tone  ;  may  both 
tones  be  produced  by  the  same  string  ? 

10.  Can  both  a  high  tone  and  a  low  tone  be  produced 
by  the  same  string? 

11.  Does  the  board  have  any  influence  upon  the  tones 
produced  ? 

12.  Move  the  bridges  a  little  closer  together  ;  what 
difference  in  sound  is  noted  ?     To  what  is  this  due  ?     If 
screw  eyes  are  used  in  one  end  of  the  board,  as  suggested 
above,    the  strings  may  be   readily   tightened  with  the 
bridges  in  any  position. 

13.  What  effect  is  produced  by  placing  the  bridges 
farther  apart  ?     To  what  is  the  effect  due  ? 

14.  What  is  the  best  size  for  the  window  opening  ? 
Would  the  harp  play  as  well  in  a  similar  opening  at  the 
top  of  the  window  ? 

15.  Can  you  see  a  reason  for  using  silk  thread?     Why 
should  it  be  waxed  ? 

16.  Can  you,  when  out  of  doors,  hear  any  sounds  which 
are  produced  in  a  way  similar  to  the  manner  in  which 
they  are  made  by  the  ^Eolian  harp  ? 

17.  What  sounds  can  you  distinguish  that  come  from 
a  different  cause  ? 

1 8.  In  the  sounds  that  you  hear  about  you  on  all  sides, 
can  you  distinguish  those  of  the  same  varieties  that  were 
produced  by  the  ^Eolian  harp  ? 

19.  What   produces   high   tones?     Low  tones?     Can 
you  distinguish  soft  tones  ?     By  what  are  the  loud  tones 
produced  ? 


May]  PHYSICS.  369 

20.  Are  there  any  sounds  produced  that  are  not  musi- 
cal ?     What  difference  do  you  notice  between  musical  and 
non-musical  sounds? 

21.  Fasten  a  stiff  wire  (a  knitting  needle  answers  the 
purpose),  eight  or  ten   inches  long  upright  in  a  vise,  or 
drive  it  into  a  board  or  block  of  wood.     Pull  the  free  end 
to  one  side  and  suddenly  let  it  go  ;  describe  what  takes 
place.     Make  a  drawing  of  the  wire,  showing  its  range  of 
movement. 

22.  For  convenience,  certain  parts  of  the  course  tra- 
versed by  the  swinging  wire  are  named  as  follows :  The 
motion  from  one  extreme  position  of  the  wire  to  the  other 
is  called  a  single  vibration ;  from  one  extreme  position  to 
the  other  and  back  again  is  a  double  vibration  or  a  com- 
plete vibration.     The   distance   from  the  middle  point  of 
a  single  vibration  to  either  extreme  is  called  the  ampli- 
tude of  vibration.     The  time  occupied  in  making  a  com- 
plete vibration  is  called  the  period  of  vibration. 

23.  Fasten  the  same  wire  used  in  (21)  in  the  vise  so  that 
but  half  its  length  shall  project  ;  what  differences  do  you 
notice  ?     Did  you  secure  a  pure  tone  in  the  first  instance  ? 
Compare  with  the  vibrations  in  the  second  position. 

24.  In  which  position  does  the  wire  have  the  greater 
period  of  vibration  ?     This  can  be  shown  if  you  place  two 
wires  in  the  vise,  one  double  the  length  of  the  other. 

25.  How  does  changing  \\\z period  affect  the  tone  ? 

26.  Cause  the  wire  to   vibrate   with  different  ampli- 
tudes ;    how  does  it  affect  the  sound  ? 

27.  Strike  one  edge  of  a  small  bell  with  a  stick  or  a  pen- 
cil ;  hold  a  small  cork  or  a  bead  suspended  by  a  thread 
so  that  it  rests  lightly  against  the  opposite  side  of  the 
bell  at  the  edge.     What  does  the  cork  tell  you  ? 

28.  Strike  a  tuning  fork  against  something,  and  while 


37°  NATURE  STUDY.  [May 

it  is  giving  out  a  tone  dip  it  quickly  into  a  glass  of  water  ; 
what  do  you  learn  from  this  ? 

29.  Strike  it  again  and  set  the  end  of  the  fork  against 
your   closed   teeth.     Try   again   and    hold   one   of   the 
prongs  just  touching  the  tip  of  the  nose  or  ear.     Can 
you  tell  what  is  producing  the  sound  in  the  fork. 

30.  Drive  a  small   nail  nearly  to  the   head  into  one 
end  of  the  table.      Stretch  from  it  across  the  table  a  fine 
wire  or  violin  string.     The  wire  may  be  obtained  at  any 
hardware  store  for  five  cents  a  spool.     Place  under  the 
string  two  bridges  similar  to  those  in  the  harp,  and  from 
its  free  end  suspend  a  small  pail  with  shot  enough  in  it 
to  make  a  weight  of  about  a  half  pound. 

31.  Pluck  the  string  with  the  finger;  can    you    follow 
the   vibration    with    the  eye  ?     Make  a  drawing   of  the 
string  with  its  attachments  and  mark  the  different  things 
described  above  in  (22). 

32.  Add  shot  until  the  pail  weighs  one  or  two  pounds, 
and  pluck  the  string  again  ;  can  you  get  a  tone  from  it  ? 

33.  Add  shot  to  the  bucket  until  the  octave  is  reached  ; 
how  much  does  the  pail  and  shot  weigh  ?     Compare  with 
the  weight  with  which  the  lower  note  was  attained. 

34.  How  does  the  increased  weight  affect  the  period  of 
vibration  ?     How  does  it  affect  the  tone  ? 

35.  Place  a  third  bridge  under  the  string,  so  that  the 
part  of  the  cord  on  one  side  of  it  will  give  the  octave  above 
that  given  by  the  whole  cord  ;    what  is  the  length  of  that 
part  of  the  cord  compared  with  the  entire  string?     Why 
should  the  third  bridge  be  no  higher  than  the  others  ? 

36.  How  does  the  period  of  vibration  of  the  segment 
compare  with  that  of  the  whole  cord  ? 

37.  Stretch   another   string,  heavier  than  the   first,  by 
the  same  weight ;  pluck  with  the  finger  and  compare  with 


May]  PHYSICS.  37 1 

that  obtained  from  the  smaller  cord.     Compare  its  period 
of  vibration. 

38.  What  changes  could  you  make  by  which  the  same 
note  could  be  obtained  from  both  ? 

39.  What  things  have  you  discovered  which   affect  the 
pitch  of  the  tone  ?     What  things  affect  the  period  of  vi- 
bration ? 

40.  Pluck  the  strings  so  that  each  will  produce  both 
loud  and  soft  tones  ;  can  you  discover  what  determines 
loudness  of  tone? 

41.  Support  in  a  horizontal  position   a  pane  of  glass, 
about  eight  or  ten  inches  square,  upon   a  block  of  wood 
half  an  inch  square.     Hold  a  glass  rod  or  piece  of  tub- 
ing, eighteen  inches  or  two  feet  long,  upright  on  the  glass 
plate  immediately  over  the  block.     Dust  a  small  cloth  well 
with  powdered  rosin,  and  holding  the  rod  firmly  with  one 
hand,  rub  the  cloth  up  and  down  it  with  the  other  until 
a   sound  is    produced.     Sprinkle   fine  dry    sand   evenly 
over  the  surface  of  the  glass  and  rub  the  rod  as  before. 

42.  What  causes  the  sand  to  move?     Note  the  dif- 
ferent effect  upon  it  of  the  shrill  and  deep  notes. 

43.  Why  does  it  lie  still  along  certain  lines  ? 

44.  If  convenient,  draw  a  violin  bow  over  the  edge  of 
the  glass.     What  effects  are  produced  by  drawing  it  over 
different  parts  ? 

45.  The   lines    along    which  *the    sand    gathers    are 
called  nodes.    Strike  a  tuning  fork    and    turn  it  round 
slowly  near  the  ear  ;  can  you  account  for  the  intermit- 
ting sounds  ? 

46.  Can   you   see   any  relation   between   the   periods 
of   silence  noticed  with  the  fork  and  the  lines  of  rest  on 
the  glass  plate  as  are  indicated  by  the  sound  ? 

47.  Hold  a  light  piece  of  paper  across  one  of  the  strings 


372  NATURE  STUDY.  [May 

mentioned  in  (37)  and  cause  it  to  vibrate  ;  can  you  see 
any  nodes  ? 

48.  Why  is  it  that  when  you  grasp  the  cord,  the  tun- 
ing fork,  the  bell,  or  the  glass  plate  in  any  of  the  forego- 
ing experiments  you  produce  silence  ? 

49.  Recall   the    singing    flame    that    was     studied    in 
Chemistry  for  January  in  the  experiment  with  hydrogen  ; 
can  you  account  for  it  ? 

50.  Why  did  changing  the  length  of   the  tube   affect 
the    sound  ?     What  causes  the   sound  when  you   blow 
across  the  mouth  of  a  hollow  key  ? 

51.  What  causes  the  sound  in  a  steam  whistle  ? 

52.  Where  is  the  sound  of  the  human  voice  produced  ; 
Place  the  finger  on  the  throat  on  "  Adam's   apple  "  and 
prolong  the  sound  of  O,  then  change  to  the  octave  above  ? 
can  you  feel  any  movement? 

53.  Try  in  the  same  way  the  long  sounds  of  all  the 
vowels  ;  do  you  notice  any  difference  in  the  throat  move- 
ments in  making  these  different  sounds  ? 

54.  The  vocal  sounds  are  produced   by  the  air  pass- 
ing over  the  edges  of  membranes  that  are  so  stretched 
across  the  larynx  as  to    form  a  narrow  slit-like  opening. 
The  larynx,  also  called  the  voice  box,  is  the  chamber-like 
modification    of  the   upper  end  of  the  windpipe.      The 
membranes  across  it  are  called  the  vocal  cords. 

55.  Can  you  tell  what  probably  takes  place  with  the 
cords  when  the  voice  is  raised  in  pitch  ?     When  it  changes 
from  soft  to  loud  ? 

56.  By  what  means  do  we  mold  words  from  the  sound 
produced  by  the  vocal  cords  ?     Practice  many  different 
sounds  until  you  understand  how  this  is  done. 

57.  Of  what  importance  is  full,  perfect  breathing  in 
using  the  voice  ? 


May]  PHYSICS.  373 

58.  In  observing  a  workman  using  a  hammer  some  dis- 
tance from  you,  can  you  hear  the  sound  as  soon  as  you  see 
the  hammer  strike  ?    Can  you  hear  a  distant    whistle  as 
soon    as   you    see    the  steam   issuing  from  it  ?      Why  is 
this  ? 

59.  Sound  travels  about  eleven  hundred  feet  per  second 
through  air.     Suppose  you  hear  a  peal  of  thunder  ten 
seconds  after  you  see  a  flash  of  lightning  ;  how  far  dis- 
tant is  the  cloud  ?     Suppose  five  minutes  afterward  you 
hear  the.peal  in  five  seconds  after  the  flash  ;  how  long  will 
it  be  before  the  storm  reaches  you  ? 

60.  Do  loud,  soft,  high,  and  low  sounds  travel  with  equal 
rapidity  ?     How  does  it  happen  that  you  can  hear  at  the 
same  time  the  music  of  many  different  instruments  play- 
ing in  a  band  at  some  distance  from  you  ? 

6 r.  What  difference  can  you  detect  between  a  musical 
tone  and  mere  noise  ?  Why  does  the  tuning  fork  give  a 
musical  tone,  while  a  stone  against  which  you  strike  it 
makes  only  a  noise  ? 

62.  Can  you  account  for  an   echo  ?     Note  the  condi- 
tions which  are  always  present  when  an  echo  is  heard. 

63.  Hang  a  watch  at  the  focus  of  a  concave  mirror  ; 
facing  the  mirror,  but  at  a  sufficient  distance  from  it  for 
the  ticking  to  be  inaudible,  place  another  concave  mirror. 
Place  a  small  funnel  in  the  end  of  a  rubber  tube,  and  with 
the  other  end  of  the  tube  held  to  the  ear,  place  the  funnel 
at  the  focus  of  the  second  mirror. 

64.  Can  you  hold  it  so  that  the  ticking  of  the  watch 
can  be  heard  ?     Why  place  the  watch  in  the  focus  ?     Why 
hold  the  funnel  in  the  focus  of  the  second  mirror  ?     Why 
use  the  funnel  ?     Why  use  the  rubber  tube  ? 

65.  The  following  table  shows  the  number  of  vibrations 


374  NATURE  STUDY.  [May 

per  second  of  each  tone  in  the  octave  below  middle  C,  and 
the  relation  of  the  numbers  in  any  octave. 

Ca         Da         EQ         F,         Ga         A2         B2         C3 

i        *        I        I       f        I      V- 

128       144       160       170       192        214       240         256 

66.  If  there  were  no  ear  in  the  world,  would  there  be 
any  sound  ? 

67.  When  a  bell  strikes,  where  does  the  sound  seem  to 
be  ?    Where  is  it  really  ? 

68.  Suppose  a  person  were  to  be  born  deaf,  and  after 
growing  to  adult  age  were  suddenly  to  acquire  the  power 
to  hear  ;  what  troubles  do  you  think  he  would  find  in  his 
new  experience  ? 

69.  What  enables  us  to  properly  locate  the  source  of 
a  sound  ?     Why  cannot  the  child  do  it  so  accurately  ? 

70.  Can  you  get   an  idea  of  sound  by  any  means  ex- 
cept  through   the  ear?     Place  a  watch  at  first  loosely 
between  the  lips  and  then  clasp  it  firmly  between  the 
teeth  ;  do  you  notice  any  difference  in  the  loudness  of 
sound  ? 

71.  Do  you  see  any  use  for  the  external  ear  ?     Why  do 
we  not  have  the  power  to  move  the  ears  as  many  other 
animals  do  ?     Of  what   advantage  to   them   are  the  ear 
movements  ?      What  different   expressions  are  possible 
with  them  by  means  of  their  ear  movements  ? 


FLAME. 

Following  the  studies  of  the  previous  months  upon  the 
different  gases,  it  will  now  be  a  matter  of  both  interest 
and  profit  to  study  flame,  with  a  view  to  seeing  how  it  is 
produced  and  of  what  parts  it  is  composed.  An  ordinary 
candle  will  serve  the  purpose,  though  a  gas  jet  would  be 
better  in  some  respects  for  part  of  the  work. 

1.  Trim  the  tallow  away  from  the  wick,  leaving  it  pro- 
jecting half  an  inch,  and  light  it  at  the  tip  ;  what  happens 
as  the  flame  increases  in  size  ? 

2.  Shield  it  from  draughts  from   doors  or  windows  ;  is 
there  any  part  visible  outside  the  luminous  cone  of  flame  ? 

To  discover  this,  hold  a  sheet  of  paper  close  to  the  flame 
so  that  the  luminous  part  is  obscured  ;  what  do  you  notice 
when  you  look  past  the  edge  of  the  paper  toward  the  outer 
edge  of  the  flame  ? 

3.  Take  a  short  glass  tube  that  is  drawn  to  a  point  and 
hold  the  large  end  in  the  blue  center  of  the  flame  with 
the  pointed  end  upward  ;  can  you  detect  any  odor  at  the 
tip? 

4.  Hold  a  lighted  match  at  the  tip  of  the  tube.    What 
does  this  indicate  ?     What  comes  up  the  tube? 

5.  Hold  a  sheet  of  writing  paper  horizontally  above  the 
flame  and  lower  it  steadily  down  in  the  flame  to  the  wick 
and  quickly  remove  it  ;  what  does  the  scorched  part  in- 
dicate ? 

375 


376  NATURE  STUDY.  [May 

6.  Hold  a  small  splinter  across  the  blaze  for  an  instant 
and  note  the  scorched  spots  ;  what   does  their  position 
indicate  concerning  the  different  parts  of  the  flame  ? 

7.  Approach  the  flame  with  a  splinter  and  notice  when 
it  takes  fire  ;  is  it  necessary  for  it  to  touch  the  luminous 
part  of  the  flame  to  ignite  ? 

8.  Does  the  wick  burn?     Is  it  the  burning  wick  that 
makes  the  large  bright  flame  ? 

9.  What  use  can  you  discover  for  the  wick  ?     What 
do  you  find  around  the  base  of  the  wick  ? 

10.  How  does  the  oil  or  melted  tallow  reach  the  blaze  ? 
What  change  does  it  undergo  when  it  reaches  the  blaze  ? 
See  question  (3)  above. 

11.  From  what  you   have  seen  can  you  tell  which  is 
the  hottest  part  of  the  flame  ?     The  coolest  ? 

12.  Hold  a  piece  of  a  dish  or  glass  for  a  moment  in 
the  luminous  part  ;  what  proves  to  be  in  this  part  of  the 
flame? 

13.  Why  is   the  center  of  the  flame  cooler   than  the 
outer  part  ?     Why  is  the  carbon  not  entirely  consumed 
in  the  luminous  zone  of  the  flame  ? 

14.  Lower  a  wire  gauze  over  the  flame  ;  does  it  burn 
above  the  gauze  ? 

15.  Hold  a  lighted  match  above  the  gauze  ;  can  you 
produce    a    flame    then    that    comes    from   the    candle  ? 
What   does    that   show  ?     Look   down    upon    the    flame 
through  the  gauze. 

16.  Roll  a  little  piece  of  gauze  around  a  lead  pencil 
and  then  lower  the  tube  over  the  flame  ;  can  you  explain 
what    happens  ?     Read    about    safety    lamps     used   by 
miners. 

17.  Examine,  in  the  same  way  as  you  have  the  candle, 
the  flame  of  your  alcohol  lamp  and  note  the  differences. 


May]  CHEMISTRY.  377 

1 8.  In  the  same  way,  also,  if  possible,  examine  a  gas 
flame. 

19.  Are  we  burning  gas  when  we  use  candles  ?     What 
gas  is  it  ?     What  forms  as  a  result  of  the  burning  of  this 
gas  in  air  ?     Hold  a  cold  plate  above  the  flame.     (See 
Chemistry  for  January.) 

BOOK  OF  REFERENCE.     Humboldt  Library  :  No.  99  ;  chapter  on 
Flame. 


There  is  no  month  in  the  year  whose  meteorological 
influence  is  more  potent  for  good  or  ill  than  May.  Upon 
its  influences  hang  the  prosperity  and  comfort,  if  not 
the  fate,  for  the  rest  of  the  season,  of  almost  every  living 
thing,  both  plant  and  animal,  in  our  latitude.  A  dry, 
windy,  warm  May  so  thoroughly  checks  and  stunts  the 
growth  of  all  sprouting  seedlings  that  hardly  any  amount 
of  favor  for  the  rest  of  the  seasen  will  enable  them  to 
make  good  their  loss.  At  this  time  the  germinating 
plants  are  just  trying  to  learn  how  to  take  their  nourish- 
ment from  the  soil,  and  they  need  no  end  of  encourage- 
ment in  rains  and  friendly  clouds  that  shield  them  from 
the  direct  rays  of  the  sun.  The  meteorology  for  the 
month  should,  therefore,  be  studied  with  interest. 

1.  How  many  frosts,  if  any,  have  you  noted  in  May  ? 

2.  Compare  May  with  the  autumn  months ;  which  one 
is  it  most  like  in  this  respect  ? 

3.  What    inference    can    you    make    respecting    the 
temperature  during  the  night  of  each  of  these  two  months  ? 

4.  How  do  the  daily  records  of  the  two  months  com- 
pare as  to  temperature  ? 

5.  Have  you  noticed  any   change  in  the  amount  of 
cloudiness    this    month  ?     Compare    with   the    autumn 
months  ;    with  the  winter  months. 

6.  Is  a  cloudy  May  favorable  or  unfavorable  ? 

7.  How  do  the  clouds  differ  in  character  from  those 
of  winter  months  ?     Can  you  explain? 

378 


May]  METEOROLOGY.  379 

8.  Compare  the  temperature  before  and  after  rainfall ; 
does  it  vary  uniformly  ? 

9.  Do  the  movements  of  the  mercurial  column  in  the 
barometer  seem  to  be  associated  in  any  way  with  the 
storms  that  have  occurred? 

10.  Compare  the  direction  of  the  prevailing  wind  with 
that  for  January. 

11.  What  wind  has  been  accompanied  by  rain  ?     What 
one  with   clearing  weather  ?     Compare   with  preceding 
months. 

12.  Under  what  circumstances  has  dew  been  formed 
this  month  ?     Have  there  been  any  fogs  ? 

13.  Compare  the  rate  of  change  of  temperature  this 
month  with  that  of  April  and  March. 

14.  What   have   been    the   extremes  of   temperature? 
Compare  with  the  autumn  months. 

15.  What  are  the  extremes  in  the  barometric  record  ? 

STUDY  OF  THE   WEATHER   BUREAU   MAPS. 

16.  In  what  quarter  of  the  country  has  the  Low  Area 
appeared  most  frequently  ? 

17.  In  which  quarter  has  there  been  the  heaviest  rain- 
fall ? 

18.  Trace  the  isothermal  line  60  Degrees  ;  compare 
with  its  course  and  location  in  April. 

19.  Is  the  isothermal  60  degrees  more  or  less  regular 
in  its  course  this  month  than  last  month  ? 

20.  Compare  in  this  particular  the  course  of  all  the 
isotherms  this  month  with  last. 

21.  Where  are  they  turned  most  widely  from  the  nor- 
mal east  and  west  line  ? 

22.  Do   the   coast  lines   affect   them   now   as  in  the 
winter  ? 


30  NATURE  STUDY.  [May 

23.  Can  you  see  any  change  in  their  course  about  the 
Great  Lakes  ? 

24.  Do  the  great  river  valleys,  the  St.  Lawrence  and 
Mississippi,  seem  to  affect  their  course  ? 

25.  What    effect    upon    them    have    the     Rocky   and 
Appalachian      mountains  ?      Compare      with     previous 
months. 


astronomy 

1.  How  much  change  in  the  length  of  day  and  night 
during  this  month  ? 

2.  Is  the  rate  of  change  increasing  or  diminishing  ? 

3.  How  does  the  rate  of  change  compare  with  that  of 
last  month  ? 

4    In  what  other  month  of  the  year  was  the  rate  of 
change  near  what  it  is  now  ? 

5.  Compare  the  positions  of  the  earth  in  its  orbit  during 
these  two  months. 

6.  Try  to  explain,  using  a  globe  when  necessary,  why 
the  rate  of  change  in  the  length  of  day  and  night  varies 
as  it  does  this  month. 

7.  Is  the  day  gaining  in  length  more  in  the  evening  or 
morning  ? 

Can  you  explain  this  ?     Compare  with  the  amount  of 
change  during  the  winter  and  fall  months. 

8.  How   is  the   position    of  the  sun   on    the    horizon, 
morning  and  evening,  changing  ?     Explain  why  it  is  so. 

9.  How  much  has  it  moved  on  the  horizon  since  March  ? 
How  much  since  December? 

10.  Compare  the  rate  of  change  in  the  noon  shadow 
with  that  of  last  month  ;  can  you  see  why  it  varies? 

i  r.  During  what  other  month  in  the  year  was  it  nearest 
its  present  position  ? 

12.  What  angle  do  the  sun's  rays  make  with  the  earth 
this  month  ?     Is  the  angle  increasing  or  diminishing  ? 

381 


382  NATURE  STUDY.  [May 

13.  How  does  the  change  of  this  angle  affect  things 
upon  the  earth  ?     Does  it  in  any  way  affect  us  ? 

14.  At  what  place  or  places  about  the  middle  of  the 
month  on  the  earth  is  the  sun  on  the  horizon  all  day  ? 

15.  It  is  said  that  in  the  polar  regions,  before  the  sun 
appears,  and  after  it  sets,  there  is  a  long  period  of  twilight ; 
can  you  explain  why  it  is  so  ?     Compare  our  twilight  now 
with  that  in  winter  ;  can  you  see  any  difference  ?     (See 
Physics  for  April.) 

1 6.  Does  the  twilight  period  increase  or  diminish  toward 
the  equator  ?     Can  you  explain  this  ? 

17.  Have  you  noticed  any  change  in  the  position  of  the 
constellations  that  were  observed  last  month  ?     In  what 
way  can  that  be  accounted  for  ? 

18.  How  have  Jupiter  and  Venus  changed  position  as 
morning  stars  since  last  month  ?     Explain  why  this  is  so. 

19.  Can  you  tell  how  much  of  its  orbit  each  has  passed 
through  since  it  became  morning  star  ? 

20.  How  much  of  its  orbit  has  the  earth  traversed  since 
then? 

21.  Additional  constellations  :  Hercules,  Lyra,  Arctu- 
rus,  and    Northern    Crown   in   the   east   in   order   from 
the  horizon  to  the  meridian. 


AFRICA.     RELIEF,    DRAINAGE,   CLIMATE,  AND 
PRODUCTIONS. 

It  will  be  noticed  that  the  structure  of  this  continent 
combines  to  some  extent  the  physical  features  of  both 
the  eastern  and  western  continents.  Its  structure  is  not 
so  simple  as  that  of  either  of  the  American  continents, 
nor  is  it,  as  yet,  nearly  so  well  known.  As  before,  the 
study  should  be  based  upon  good  physical  maps,  and 
should  be  accompanied  by  modeling  and  drawing. 

1.  Which  ocean  receives  the  largest  rivers  ?     What  is 
the  direction  of  the  greatest  highland  ? 

2.  Compare  the  direction  of  this  highland  with  that  of 
North  America.     With  South  America. 

3.  In  what  respect  does  the  northern  part  of  Africa 
resemble  the  continent  of  Euro-Asia? 

4.  In  what  respect  does  the  southern  part  resemble  the 
Americas  ? 

5.  Where  is  the  highest  point  in  the  principal  highland  ? 

6.  Where  are  the  secondary  highlands  ?     Compare  their 
position  with  respect  to  the  main  highland  with  that  in 
the  other  continents  previously  studied. 

7.  The  navigation  of  the  rivers  is  greatly  hindered  by 
rapids  and  waterfalls  ;  can  you  see  a  reason  for  this  ? 

8.  Compare  the  direction  of  the  great  rivers  of  Africa 
with  that  of  the  greatest  rivers  of  other  continents. 

383 


34  NATURE  STUDY.  [May 

9.  Compare  Africa  with  respect  to  its  lakes,  both  in 
size  and  number,  with  the  other  continents. 

10.  From  what  region  do  the  great  rivers  derive  their 
waters  ? 

11.  Compare  the  rivers  of  Africa  with  those  of  America 
with  respect  to  tributaries  ;  can  you  account  for  the  con- 
trasts observed  ? 

12.  Where  are  the  fertile  regions  in  Africa?     Can  you 
account  for  them  ? 

13.  What  influences  tend  to  make  the  coasts  fertile  and 
the  interior  barren  ? 

14.  Note  carefully  the  boundaries  of  the  Sahara  Desert ; 
can  you  understand  why  they  are  fixed  when  you  find  them  ? 

15.  What  causes  can  you  assign  for  the  position  of  this 
desert  ?     Note  the  direction  of  the  winds  as  indicated  by 
the  arrows  on  a  good  physical  map. 

16.  Compare  the  region  in  the  same  latitude  in  America  ; 
do  you  find  a  desert  ?     Can  you  see  a  reason  ? 

17.  Compare  with  the  different  parts  in  Asia  in  the  same 
latitude  ;  what  contrast  do  you  find  ? 

1 8.  Do  any  rain-bearing  winds  reach  Africa  from  the 
Atlantic  Ocean  ?     Why  ? 

19.  Can  you  see  any  reason  for  desert  regions  in  the 
southern  part  of  the  continent  ? 

20.  Compare  with  South  America  in  the  same  latitude  ; 
is  there  similarity  or  contrast  ? 

2 1 .  Compare  the  equatorial  regions  of  Africa  and  South 
America  ;  which  region  has  the  more  luxuriant  vegetation  ? 
In  which  is  animal  life  more  abundant  ? 

22.  What  has  determined  the  location  of  the  cities  in 
Africa  ?     Contrast  their  location  with  that  of  the  cities  of 
other  countries. 

23.  Can  you  see  what  things  have  contributed  to  give 


May]  GEOGRAPHY.  385 

Egypt  so  conspicuous  a  place  in  history  ?     Compare  and 
contrast  its  natural  advantages  with  Italy  and  Greece. 

24.  What  are  the  natural  obstacles  in  the  way  of  African 
exploration  ?     What  physical  features  stand  in  the  way  of 
trade  ? 

25.  What  are  the  valuable  productions  in  the  tropical 
interior  ?     How  are  they  carried  to  the  cities  ? 

26.  Why  is  it  that  there  are  no  cities  in  the  centers  of 
these  productions  as  in  other  continents  ? 

27.  Where  are  the  mining  regions  ?     What  minerals  are 
found  ? 

28.  By  whom  are  the  mines  worked  ? 

29.  What  contrasts  are  found  in  the  continent  of  Africa 
and  South  America  in  the  same  latitude  ? 


FIELD   LESSONS. 

The  importance  of  doing  a  great  deal  of  field  work  with 
beginners  in  geology  cannot  be  overestimated.  In  fact, 
there  is  but  one  way  to  begin,  and  that  is  by  going  into 
the  field.  Such  lessons  are  often  less  fruitful  than  they 
might  be  because  of  a  lack  of  system  in  the  plan  for  it. 
From  the  beginning  of  this  month  on  to  the  end  of  the 
school  year,  the  season  is  likely  to  be  suitable  for  outdoor 
work,  and  a  few  hints  as  to  the  mode  of  conducting  a  field 
lesson  will  be  found  useful. 

As  a  rule  it  is  best  to  have  a  definite  thing  to  look  for  or 
to  study  each  time  a  field  lesson  is  undertaken.  Sometimes 
all  hope  of  good  results  is  lost  by  calling  it  a  picnic.  This 
term  has  a  distinctive  meaning  of  its  own  in  the  minds  of 
the  children,  and  it  has  but  little  in  common  with  serious 
study.  The  pupils  should  be  provided  with  baskets  or 
bags  in  which  they  may  carry  the  specimens  gathered,  and 
there  should  be  a  number  of  good  hammers  in  the  class. 
A  small  pocket  compass  will  also  be  found  useful  in  get- 
ting the  exact  direction  of  the  dip  and  strike  of  rock.  For 
getting  the  angle  of  the  dip  use  the  instrument  described 
under  Astronomy  for  September,  on  page  61.  If  a  lake 
or  stream  is  visited,  a  small  wide-mouthed  bottle  will  be 
needed  in  which  some  water  may  be  obtained  and  allowed 
to  settle  to  show  the  amount  of  silt  in  suspension.  It  should 

386 


May]  GEOLOGY.  387 

be  definitely  understood  at  the  outset  that  each  pupil  will 
be  held  responsible  for  a  description  of  what  he  has  seen, 
to  be  expressed  in  writing,  a  drawing,  a  painting,  a  clay 
or  sand  model,  as  may  best  be  adapted  to  the  particular 
circumstances  of  the  case.  All  true  education  must  de- 
velop three  great  ideas — those  of  space,  time,  and  force,  and 
the  field  lesson  gives  capital  opportunity  to  broaden  all 
three.  A  few  suggestive  questions  are  appended. 

1.  What  is  the  size  of  the  area  you  wish  to  study  ?   Its 
length  ?   Its  breadth?     Its  area  in  square  miles  or  acres? 

The  area  selected  must  not  be  too  large.  Take  only 
so  much  as  will  be  needed  to  illustrate  the  point  it  is  de- 
sired to  study. 

2.  What  forces  have  given  the  surface  its  chief  char- 
acter ?     Are  they  still  at  work  ?     Have  the  organic  or  in- 
organic agencies  done  most  of  the  work  ? 

3.  Has  the  work  within  the  selected  area  been  one  of 
building  or  tearing  down  ?     If  tearing  down,  what  counter 
forces  have  retarded  it  ?     If  building,  what  counter  forces 
have  opposed  ? 

4.  Which    of   the   inorganic   agencies,  rain, -snow,  ice, 
frost,  etc.,  have  been  the  most  active  ? 

5.  Have  any  forces  acted  here  in  the  past  which  are 
now  quiescent  ? 

6.  Note  the  work  of  running  and  standing  water,  if  there 
be  any  ;  is  it  destructive  or  constructive  ? 

7.  Note  the  soil  and  subsoil,  and  compare  both  with  the 
underlying  rock,  if  any  is  to  be  found.     How  was  the  soil 
formed  ? 

8.  Are  the  underlying  rock  strata  horizontal  or  inclined  ? 
What  is  the  amount  and  direction  of  dip  in  different  places  ? 

9.  Are  there  fossils  in  the   rocks  ?     Are  they  fossils  of 
animals  or  plants  ?     Land   or  water  ?     Fresh   water   or 


NATURE  STUDY.  [May 

marine  ?  Are  there  any  forms  like  them  living  at  pres- 
ent ?  What  present  forms  do  they  most  closely  resem- 
ble ? 

10.  If  a  stream  is  studied,  consider  the  course  of  the 
channel ;  is  it  changing  at  present  ?     How  far  has  it  in 
the  past  deviated  from  its  present  course  ? 

11.  Does  the  water  contain  silt  in  suspension  ?     Test 
by  allowing  a  bottle  full  to  stand  until  it  settles.     Is  the 
water  soft  or  hard  ?     Why  ? 

12.  Are  there  any  springs?     Are  they  constant  or  in- 
termittent ?     Are  they  greatly  and  suddenly  affected  by  a 
heavy  rain  ?     Have  you  any  means  of  telling  whether  the 
underground  reservoir  is  deep  or  near  the  surface  ?     Does 
the   water  form  a  deposition   near   the   outlet  ?     What 
is  it? 

13.  If  a  standing  body  of  water  is  present,  can  you  tell 
what  the  source  of  the  water  is  ?     What  hollowed  out  the 
basin  that  holds  the  water  ?     Why  does  the  water  not  sink 
into  the  earth  ?     Is  there  an  outlet  ?     Did  it  always  oc- 
cupy the  spot  it  now  does  ?     Is  it  changing  its  limits  now  ? 
What  is  the  cause  of  it  ?     Is  there  silt  suspended  in  the 
water  ? 

14.  For  suggestions  as  to  the  study  of  a  marsh,  see 
Geology  for  April.     See,  also,  Geology  for  September. 

15.  On  the  ground  make  necessary  measurements  and 
sketches,  and  on  returning  make  (a)  drawings  showing  the 
outline  of  the   area  studied,  the   course  of  the  streams, 
etc.     (b)  A   model    in  clay  or   sand,   showing  the  chief 
features   of  relief,    direction    of    elevations,  valleys,  de- 
pressions rilled  with  water,  springs,  etc.     (c)  Drawing  or 
painting,  or  both,  showing  the  rock  strata,  their  colors, 
dip,  fossils,  etc.     (d)  A  written  description  of  the  special 
features  of  the  lesson  ;  this   may   include   description  of 


May]  GEOLOGY.  389 

the  soil,  of  the  characteristic  vegetation,  and  the  probable 
geological  history  of  the  region.  Any  or  all  of  these 
modes  of  expression  should  be  required  at  the  discretion 
of  the  teacher  as  the  age  of  the  pupils  and  the  demands 
of  the  lesson  may  seem  to  require. 


EXAMINATION   OF   SOILS. 

One  of  the  most  obvious  things  to  any  one  who  makes 
a  study  of  plant  life  is  the  close  relation  which  exists  be- 
tween the  growth  of  a  plant  and  the  character  of  the  soil 
that  produces  it.  For  this  reason  something  should  be 
done  in  the  course  of  the  season  to  lead  to  a  more  or  less 
close  examination  of  the  different  soils  in  which  plants 
are  found  growing.  The  work  must  of  necessity  be 
mostly  of  a  qualitative  nature,  and  even  in  this  line  only 
the  simplest  things  can  be  noticed.  It  is  well  to  keep  in 
mind  during  the  study  that  the  fertility  of  soil  de- 
pends upon  its  physical  and  chemical  nature.  A  know- 
ledge of  these  properties  is  of  great  practical  value  in 
determining  what  plant  food,  if  any,  should  be  added 
to  it,  and  also  what  classes  of  plants  are  best  adapted  to 
it.  Some  care  should  be  used  in  selecting  a  specimen 
for  examination.  Try  to  secure  a  block  of  it  a  few  inches 
square  and  as  deep  as  the  soil  is  to  be  found.  Portions 
of  it  may  then  be  examined  in  the  order  in  which  it  actu- 
ally occurs  in  the  ground. 

It  is  thought  best  to  briefly  outline  the  entire  pro- 
cess for  the  mechanical  analysis  of  soils,  though  the 
wise  teacher  will  decide  whether  it  is  best  to  have  his 
pupils  go  through  with  it  all  at  once.  Problems  may  be 
given  at  different  times  as  occasion  requires,  such  as  : 

39° 


May]  MINERALOGY.  391 

To  find  the  amount  of  clay  in  a  certain  soil ;  or,  To  ascer- 
tain the  amount  of  gravel,  or  coarse  sand,  etc. 

1.  What  depth  is  the  soil  where  you  have  examined 
it  ?     What  kind   of  subsoil   is   underneath  ?     Subsoil  is 
the  layer  immediately  below  the  surface  soil. 

2.  What  depth  is  there  to  the  subsoil  ? 

3.  How  has  the   soil   been  formed  ?     Is  it  made  by 
the  rotting  away  of  the  underlying  rock,  or  has  it  been 
carried  to  its  present  place  from  a  distance  ? 

4.  What  part  have  plants  played  in  forming  the  soil  ? 

5.  How  does  the  subsoil  differ  from  the  soil  ? 

6.  Has  the  slant  or  position  of  the  field  had  anything 
to  do  with  the  formation  of  the  soil  ? 

7.  Has  the  soil  ever  had  any  fertilizers  added  to  it 
artificially  to  increase  its  productiveness? 

8.  Dry  a  small  amount  of  the  soil,  rub   up  finely   the 
earthy  lumps,  and  pick  out  the  small  stones  it  may  con- 
tain ;  are  they  of  one,  or  different  kinds  ?     Use  some  of 
the  tests  mentioned  in  the  previous  lessons  to  determine 
some  of  their  properties. 

9.  Weigh  about  three  or  four  ounces  of  the  dried  soil 
and   pass   it  through  a  small  sieve  made  from  gauze  in 
which  the  meshes  are  one-tenth  of  an  inch  apart.     Rub  up 
the  earthy  lumps  so   that  all  the  fine  material  will   pass 
through. 

10.  Wash  the  part  too  coarse  to  pass  through  until  thor- 
oughly free  from  dirt,  and  dry  and  weigh  it.     How  much 
coarse  gravel  do,  you  find  in  the  soil?     What  per  cent, 
of  its  entire  weight  ? 

11.  Take  that  part  of  the  soil  which  passed  through  the 
sieve  and  rub   it   through  another,  the  meshes  of  which 
are  one-fifteenth  of  an  inch  apart. 

12.  Again  take  the  part  that  is  too  coarse  to  go  through. 


392  NATURE  STUDY.  [May 

and  wash,  dry,  and  weigh  ;  this  will  give  the  amount  of 
gravelly  sand  in  the  soil.     What  per  cent,  is  there  ? 

13.  Weigh  a  small  amount  of  this  gravelly  sand  and 
heat  it  red  hot  for  some  time   in    a   small  crucible  and 
weigh  again  ;  does  it  lose  weight  when  burnt  thus  ?     Why  ? 

14.  Take   an    ounce  of    the    fine    material    that  has 
passed  through  the  second  sieve  and  boil  it  in  a  flask  un- 
til all  the  particles  are  completely  separated.    When  cool, 
rinse  it  out  into  a  tall  jar  or  bottle  with  a  wide  mouth. 
By  means  of  a  funnel  and  long  tube  reaching  nearly  to 
the  bottom  pour  a  gentle  stream  of  water  into  the  jar  so 
as  to  agitate  the  sediment.     Set  the  jar  in  a  larger  vessel 
and  catch  the  overflow. 

15.  When  the  water  runs  away  clear,  pour  off  the  water 
and  dry  the  remainder  ;  this  will  give  the  coarse  sand 
in  the  soil.     What  per  cent,  of  the  soil  is  it  ? 

16.  Weigh  a  small  amount  of  it  after  it  is  dried  and 
then  heat  it  red  hot  in  a  crucible  ;  does  it  lose  weight  ? 
Why  ?     What  kind  of  substances  burn  ?     What  kind  can- 
not be  consumed  in  the  fire  ? 

17.  Repeat   the    process   described    above    with   the 
overflow  from  the  jar  ;  this  will   give  the  fine  sand.     Do 
not  agitate  so  strongly  as  in  the  first  instance.     Does  it 
lose  weight  by  being  burned  ? 

1 8.  Subtract  the  weight  of  the  coarse  and  fine  sand  from 
the  weight  taken  in  the  beginning  and  it  will  give  the 
amount  of  clay  in  the  soil.     What  per  cent,  is  it  of  the 
whole  amount  ? 

19.  Where  does  the  sand  come  from   that  you  have 
found  in  your  sample  of  soil  ?     Was  it  derived  from  the 
underlying  rock  ? 

20.  Can  you  account  for  the  presence  of  the'  gravel 
that  you  found  ?     Are  the  pebbles  all  of  the  same  kind  ? 


May]  CHEMISTRY.  393 

21.  Where  did  the  clay  come  from  ? 

22.  How  was  that  part  of  the  soil  formed  that  was  con- 
sumed in  the  fire  when  heated  ? 

23.  Which  element  found  in  the  soil  is  best  for  vegeta- 
tion ?     Which  is  the  poorest  ? 

24.  Why  is  gravel  poorly  adapted  for  plants  ?     Does 
its  presence  add  or  detract  from  the  fertility  of  the  soil  ? 

25.  What   are   the   advantages    and   disadvantages  of 
sand  for  vegetation  ? 

26.  Which  is  better  for  plants,  clay  or  sand  ?     Why  ? 

27.  What   properties   of   loam   make   it   valuable   for 
plants  ? 


At  this  season  of  the  year,  the  material  which  might  be 
taken  up  in  this  subject  for  study  has  become  so  abun- 
dant that  it  is  difficult  to  make  a  selection.  The  decision 
as  to  what  shall  be  studied  may  be  left,  partly  at  least,  to 
the  pupils  themselves,  due  regard  being  given  to  the  ease 
with  which  specimens  may  be  obtained. 

Insect  life  presents  great  variety,  and,  also,  abundance 
of  interesting  material  upon  which  many  profitable  les- 
sons may  be  given.  Enough  work  should  be  done  along 
this  line  to  lead  the  pupils  into  inquiry  concerning  the 
habits  of  the  various  kinds  found,  their  relations  to  plants, 
and  the  structures  by  which  they  are  adapted  to  their 
modes  of  life. 

It  will  be  possible  during  this  month  to  observe  the 
newly  hatched  birds  and  the  treatment  they  receive  from 
the  old  ones.  The  work  of  the  earthworms  may  be  fol- 
lowed up  according  to  the  suggestions  offered  for  the 
previous  month  and,  in  fact,  any  of  the  work  begun  in 
the  spring  may  be  continued  now. 

BIRDS. 

1.  Upon  what  kinds  of  food  are  the  young  birds  fed  ? 
Do  the  old  ones  prepare  it  in  any  way  for  the  young 
birds  ? 

2.  What  feathers  appear  first  upon  the  young  birds  ? 

3.  Do  the  feathers  grow  evenly  over  all  parts  of  the 

394 


June]  ZOOLOGY.  395 

body  ?     Can  you  see  any  reason  why  certain  spaces  are 
left  bare  ? 

4.  How  long  after  hatching  is  it  when  the  young  birds 
attempt  to  fly  ?     Do  the  old  birds  render  the  young  ones 
any  assistance  ? 

5.  Which   parent   do  the  young  ones  resemble   more 
closely  ?     Can  you  see  a  reason  for  it  ? 

6.  What  dangers  threaten  the  young  ones  at  this  time  ? 

7.  What  evidences  do  you  have  that  bear   upon   the 
chances  of  the  young  birds  for  life  ?     Compare  with  the 
chances  of  infantile  human  life. 

8.  What  are  the  most  active  destroyers  of  bird  life  ? 
What  means  of  escape  have  they  ? 

9.  Select  feathers  from  different  parts  of  the  body  and 
compare  them. 

10.  In  a  large  quill-feather  selected  from  the  wing,  note 
the  following  points  :  (a)  the  central  shaft  bearing  on 
both  sides,  (b)  the  vane ;   (c)  the  quill,  that  part  of  the 
shaft  below  the  vane.     The  small  branches  making   up 
the  vane  are  called  barbs  ;  these  are  interlocked  by  means 
of  the  barbules.     Note  how  this  is  done.     Why  is  it  so  ? 

n.  Compare  a  down  feather  with  a  quill ;  where  is  the 
chief  difference  ?  What  difference  in  use  is  there  between 
the  down  and  quill-feathers  ? 

12.  Are  the  feathers  waterproof  ?     Explain. 

13.  Note  the  arrangement  of  the  feathers  in  the  wings  ; 
what  form  do  they  give  to  the  wing  ? 

14.  Do  you  know  of  any  long  legged  birds  that  have 
long  tails  ?     Have  you  seen  any  short  legged  birds  with 
very  small  tails  ?     What  have  you  noticed  about  the  flight 
of  such  birds  ?     When  a  bird  is  flying,  is  its  neck  stretched 
out  or  drawn  back  ?     Can  you  see  a  reason  ? 

15.  Can  you  see  what  determines  the  line  of  flight  of 


396  NATURE   STUDY.  [June 

a  bird  ?     Note  the  form  and  relative  size  of  the  body, 
wings,  tail,  and  legs. 

16.  Try  to  count  the  strokes  of  the  wings  of  different 
birds  while  they  are  flying  ;  can  you  move  your  arms  for 
five  minutes  with  equal  rapidity  ? 

INSECTS.     {See,  also,  Zoology  for  September.} 
Bees. 

1.  Watch  closely  a  bee,  either  bumble  bee  or  honey 
bee,  in   its  visits  among  flowers  ;  can  you  tell  why  its 
visits  are  made  ? 

2.  Do  they  visit  different  flowers  promiscuously  or  only 
those  of  the  same  kind  ? 

3.  Do    honey    bees  and    bumble  bees  visit  the  same 
flowers  ?     Examine  the  bees  closely  for  a  reason  for  what 
you  observe. 

4.  By  what  means  do  they  cling  to  the  flowers?     How 
do  they  examine  a  flower  ? 

5.  Do  they  injure  the  flowers  by  their  visits  ?     Can  you 
see   what    they    carry    away  ?     Examine    their  legs  and 
backs. 

6.  Can  you  see  any  use  for  the  hairs  that  are  found  on 
the  bee's  legs  and  body  ? 

7.  How  do. they  manage  to  reach  the  nectar  of  the 
flower  ?     Can  you  see  how  they  carry  it  ?     The  nectar  is 
stored  up  in  the  crop — one  of  the  divisions  of  the  alimen- 
tary canal — and  is  then  elaborated  or  changed  into  honey 
by  a  process  not  yet  fully  explained. 

8.  How  do  bees  hum  ?     Is  it  always  on  the  same  key  ? 
Can  you    tell   how   rapidly    the    wings     vibrate?     (See 
Physics  for  May  under    Sound.)     Compare    the   wings 
with  those  of  the  butterfly  and  beetle. 


June]  ZOOLOGY.  397 

9.  Can  you  find  any  evidence  of  sight  or  hearing  ?     If 
so,  can  you  locate  the  organs? 

10.  When  a  bee  has  secured  its  load,  notice  its  flight  ; 
is  a  "  bee-line  "  a  straight  line  ? 

Ants. 

Suggestions  have  already  been  made  as  to  how  ants 
may  be  confined  for  the  purposes  of  indoor  observa- 
tion. (See  Zoology  for  October.)  But  it  is  of  great 
interest  to  observe  them  at  work  at  this  season  outdoors. 
Ant-hills  are  to  be  found  in  almost  every  field  or  bit  of 
woodland  where  the  soil  is  rather  light  and  dry.  Along 
paths  and  roadsides  the  work  of  a  small  red  ant  may  be 
observed. 

1.  Do   ants    and   earthworms    work   together   in   the 
same  soils  ?     Can  you  see  any  reasons  for  the  difference 
in  the  locations  that  are  chosen  ? 

2.  Look  into  the  nests  and  secure  if  possible  some  of 
the  small,  almost  cylindrical  bodies  usually  to  be  found, 
which  most  people  call  eggs  ;  are  they  eggs  ?     Can  you 
find  eggs  ? 

3.  Do  the  ants  move  them  regularly  ?     When  do  they 
bring  them  out  ?     When  do  they  take  them  back  ?     What 
is  accomplished  by  this  care  ? 

4.  How  do  they  carry  their  burdens  ?     Can  you  trace 
any  resemblance  to  the  crawfish  ? 

5.  Can  they  see  or  hear  ?     Can  you  find  either  eyes  or 
ears  ? 

6.  What  do  they  eat  ?     Can  you  tell  from  their  mouths 
which  they  prefer,  solid  or  liquid  food  ? 

7.  If  you  can  find  a  densely  populated  ant-hill,  place 
in  it  or  near  it  a  dead  mouse  inclosed  in  a  box.     Leave 
entrances  for  the  ants,  and  you  will  not  only  feed  the 


398  NATURE   STUDY.  [June 

ants,  but;  by  and  by,  you  will  have  a  nicely  prepared 
mouse's  skeleton  for  yourself. 

8.  Can  you  find  any  small  plant  lice  on  plants   near 
the  ants'  home?     If   so,  watch  closely  and  try  to   find 
out  whether  or  not  the  ants  take  any  notice  of  them. 

9.  Do  the  ants  store  up  food  as  the  bees  do  ?     How 
do  they  employ  their  time  ?     Have  they  honestly  earned 
their  reputation  for  industry  ? 

10.  Do  ants  of  different   sizes  live  together ;  are  they 
the  same  or  of  different  kinds  ?     Do  ants  living  in  dif- 
ferent hills  communicate   with   each   other?     Are    they 
friendly  or  hostile  ?     Try  placing  strangers  in  one  of  the 

hills. 

Spiders. 

1.  In  what  locations  do  you  find  spiders?    Select  one 
or  more  places  for  observation,  and,  if  possible,  try  to 
observe  one  spinning  a  web. 

2.  How  is  the  silk  obtained  for  the  web  ? 

3.  What  feet  do  they  use  in  fastening  their  silk  as  it  is 
spun  ?     How  do  they  place  their  long  guys  which  sus- 
pend the  web  ?     Do  they  repair  old  or  broken  webs? 

4.  Where  do  they  begin  to  spin  the  circular  threads, 
in  the  middle  or  at  the  circumference  of  the  web  ?    At 
what  time  do  they  spin  the  web  ? 

5.  Examine  some  of  the  filmy  webs  that  may  be  found 
on  the  roadside  ;  how  do  they  differ  from  those  that  are 
suspended  ?  where   do    you  find   the  spider  ?     To  dis- 
cover his  whereabouts  drop  a  fly  on  the  web  or  shake  it 
slightly. 

6.  In  what  position  does  the  spider  place  himself  in 
one  of  the  suspended  wheel-like  nests  ?     Why  ? 

7.  Do  they  eat  solid  or  liquid  food  ?     Do  they  make 
any  use  of  plant  food  ? 


June]  ZOOLOGY.  390 

8.  Where    do    they    lay  their   eggs  ?     Sometimes    the 
mother  spider  may  be  seen  carrying  a  large  v\  hite  ball  ; 
what  is  it  ? 

9.  In  what   way  is   the   use   of   the    spider's    cocoon 
different  from  that  of  the  moth  ? 

10.  Can  you  discover  the  way  in  which  the   mother 
spider  cares  for  her  young  ? 

11.  How   does   the  spider  differ  in  its  structure  from 
the  bee  and  ant  ?     Compare  as  to  the  number  of  legs, 
parts  of  the  body,  etc. 

The  House-fly. 

1.  Place  a  grain  or  two  of  moistened  sugar  upon  a 
table  and  notice  how  a  fly  takes  it  up  ;  does  it  eat  it  as 
a  solid  ? 

2.  How  do  its  mouth  parts  differ  from  those  of  the  ant  ? 

3.  Does  it  make  any   use  of  its  feet  in  eating  ?     By 
moving  a  magnifying  glass  up  cautiously,   the  mode  of 
managing  food  may  be  clearly  made  out.     It  is  an  in- 
teresting  observation.     Can    you    account   for   various 
movements  it  makes  with  its  legs  and  wings  at  intervals 
while  eating. 

4.  What  evidence  have  you  that  it  can  see  ?     Can  you 
determine  whether  it  can  hear  ? 

5.  Does  it  move  its  legs  in  the  same  order  as  the  ant  ? 

6.  Examine  its  foot ;  can  you  account  for  the  way  by 
which  it  clings  to  a  pane  of  glass  or  the  ceiling  ? 

7.  Can  you  find  any  evidence  that  it  breathes  ? 

8.  Has  it  the  sense  of  smell?     Do  not  guess  at  the 
answers,  but  find  actual  proof  from  close  observation. 

9.  Where  do  they  lay  their  eggs  ?     What  comes  directly 
from  the  egg  ?     Compare  with  the  ant,  the  bee,  and  the 
spider.     A  small  piece  of  meat  exposed  to  the  warm  sun 


400  NATURE  STUDY.  [June 

will  very  soon  enable  the  pupils  to  see  the  early  stages 
of  a  fly's  life.  Is  it  the  house-fly  that  lays  its  eggs  upon 
meat  ? 

10.  Can  you  tell  how  many  vibrations  the  wings  make 
in  a  second  ?  (See  Physics  for  May.)  Compare  with 
a  bee. 

Beetles. 

1.  These  are  at  once  recognized  by  the  hard  shiny 
coats  and  wings.     Where  are  they  most  abundant  ? 

2.  Can  you  see  a  good  reason  for  the  contrast  between 
the  beetle  and  bee  in  regard  to  their  wings  ? 

3.  How  are  the  wings  employed  in  flying  ?     Can  you 
find  any  beetles  that  do  not  fly  ? 

4.  Can  you  find  any  beetles  that  do  not    spread   or 
open  the  outer  wings  ? 

5.  What  is  the  food  of  beetles  ?     Examine  the  mouth 
parts  ;  compare  with  the  fly,  the  ant,  and  the  spider. 

6.  Can  they  see  or  hear  ?     Where  are  the  organs  of 
seeing  and  hearing  ? 

7.  What  enemies  do  they  have  ?     How  do  they  es- 
cape ?     Have  they  means  of  attack  or  defense  ? 

8.  Can   you    find   any   insects   that   are   injurious   to 
plants  ? 

9.  Have  you  found  any  that  are  beneficial  to  plants  ? 

10.  Have  you  found  any  insects  that  are  either  bene- 
ficial or  injurious  to  man  ? 

REPTILES. 

It  would  be  nothing  less  than  wonderful  for  the  season 
to  pass  by  without  one  or  more  members  of  this  group 
of  animals  being  found  and  brought  in  by  some  of  the 
pupils.  Turtles  are  abundant  in  streams,  usually,  and 
are  easily  kept  in  an  aquarium  or  even  in  a  pail  of 


June]  ZOOLOGY.  4OI 

water.  A  small  piece  of  raw  meat  now  and  then  is  all 
the  food  they  require.  A  snake,  repulsive  as  it  is  to  most 
people,  is  nevertheless  an  interesting  object  for  study. 
The  teacher  should  rise  above  his  unnatural  prejudices 
against  this  creature  for  the  sake  of  the  children  who  are 
dependent  upon  him  for  the  truth  concerning  nature, 
and  try  to  have  them  grow  up  with  less  of  the  unnatural 
horror  than  he  has  himself. 

Snakes. 

1.  A  snake  may  be  kept  in  a  box  with  a  glass  cover 
over  it.     There  should  be  a  little  dried  grass  or  other 
material  in  the  box  to  afford  at  least  partial  means  of  con- 
cealment. 

2.  Can  you  discover  any  signs  of  intelligence  ?     Does 
it  show  signs  of  fear  ? 

3.  What  is  the  meaning  of  the  frequent  darting  out  of 
the  tongue  ?     Many  people  have  an  idea  that  this  is  a 
weapon  of  defense  or  attack  ;  is  it  so  ? 

4.  It  is  interesting  to  see  the  small  striped  garter  snake 
capture  its  prey  ;  put  a  mouse  in  the  box  and  watch  the 
operation.     If  you  can  find  a  poisonous  snake  compare 
the  two  in  this  respect. 

5.  Turn  the  box  upside  down  so  that  the  snake  will 
lie  on  the   glass  ;  can   you   see  from  beneath    how   the 
snake  moves  ? 

6.  Compare  its  motions  with  those  of  the  earthworm. 

7.  Do  the  scales    on  the  under  side  play  the   same 
part  that  the  spines  of  the  earthworm  do  ?     How  do  the 
scales  on  the  sides  differ  from  those  on  the  under  side  ? 

8.  Is  the  snake  propelled  by  means  of  the  scales  alone  ? 

9.  Does  the  snake  wink  ?     Compare  with  the  turtle. 

10.  Are  the  upper  and  under  sides  of  the  snake  more 


402  NATURE  STUDY.  [June 

or   less    unlike   than    in    the   case   of   the   earthworm  ? 
What  reason  can  you  give  ? 

Turtles. 

1.  How  does  the  turtle  compare  with  the  snake  as  to 
intelligence  ?     As   to    activity  ?     As   to   expressions   of 
fear? 

2.  Does  it   have   any   actions   or  habits  in    common 
with  snakes  ?     What  differences  ? 

3.  What  would  seem  to  be  the  use  of  the  hard  shell? 
Compare  the  shells  of  water  turtles  with   those  found 
on  dry  land  ;  can  you  see  a  reason  for  the  differences  ? 

4.  Do  turtles  chew  their  food  ?     How  do  they  seize  it  ? 

5.  By    what    means    do    they    swim  ?     Compare    the 
swimming  powers  with  a  fish  and  a  frog. 

6.  Has  it  any  advantages  over  either  ?     Are  there  any 
disadvantages  ? 

7.  Does  it    wink  ?     Are  you   reminded    of  any   other 
animal  examined  in  this  respect  ? 

8.  What  modes  of  attack  have  they  ?     What  are  their 
enemies  ? 

9.  Turtles  lay  their  eggs  at  this  season  in  the  sand  on 
the  shores  of  streams  and  ponds  ;  try  to  find  a  nest. 

10.  Note  their  breathing,  and  compare  with  the  snake, 
frog,  and  bird. 


Botany 

In  elementary  work  in  the  subject  of  botany,  usually, 
comparatively  little  is  planned  in  any  practical  manner 
for  a  study  of  plant  physiology.  It  is  not  difficult,  how- 
ever, for  the  pupils  to  perform  a  number  of  experiments 
which  will  do  much  in  illustrating  plant  action.  By 
similar  means,  some  notion  of  the  chief  constituents  of 
the  plant  may  be  gained. 

1.  Carefully   remove  from  the  soil  any  small  vigorous 
plant  having  a  number  of  leaves.     Gently  wash  away  the 
adhering  earth  and  dry  with  a  cloth  or  blotting  paper, 
and  weigh  it  as  accurately  as  possible. 

2.  Place  in  an  oven  or  near  the   fire  and  dry  it  com- 
pletely without  scorching,  and  then  weigh  it  again  ;  how 
much  loss  by  drying  ?     What  per  cent.  ?     What  part  of 
the  plant's  constituents  remain  ? 

3.  What  caused  the  plant  to  lose  weight  ?     Let  different 
pupils  try  different   plants.     Try  the   same  plant  in  dif- 
ferent locations  ;  how  does  the  location  affect  the  loss 
per  cent.  ? 

4.  After  finding  the  loss  of  weight,  cut  or  break  the 
dried  plant  into  small  pieces  and  heat  them  in  a  test  tube 
or  crucible   until  no  further  change  takes  place  ;  what 
now  remains  ?     What  was  formed  before  the  final  residue 
was  obtained  ?     What  became  of  this  as   change  took 
place  ?     (See  Chemistry  for  December  and  February.) 

5.  Weigh  the  residue  found  in  (4)  and  find  what  per 

403 


404  NATURE   STUDY.  [June 

cent,  it  is  of  the  fresh  plant.     What  per  cent,  is  it  of  the 
dried  plant  ? 

6.  Test  the  residue  with  a  little  hydrochloric  acid  ;  is 
there  any  action  ? 

7.  Stir  up  a  little  of  the  residue  with  distilled  water 
and  test  with  litmus  paper.    (See  Mineralogy  for  April.) 
Can  you  determine  anything  regarding  the  character  of 
the  residue  after  burning? 

8.  In  the  same  way  tests  may  be  applied  to  different 
kinds  of  wood,  leaves,  bark,  etc.  ;  what  part  of  the  plant 
has  the  most  dry,  solid  matter  ?     Which  part  the  most 
carbon  ? 

9.  Remove  from  the  ground  any  small  healthy  plant 
and  cleanse  the  roots  as  before.     A  seedling  maple  or 
ash,  or  any  woody  plant  is  to  be  preferred.     The  top  of 
the  plant  should  not  be  too  large  to  be  covered  by  a 
tumbler  or  small  glass  jar. 

10.  Cut  a  piece  of  cardboard  large  enough  to  support 
an  inverted  tumbler,  and  through  a  hole  in  the  center 
pass  the  roots  and  part  of  the  stem  of  the  plant.     Seal  the 
opening  about  the  stem  with  tallow  or  wax  and  suspend 
the  roots  in  a  wide-mouthed  bottle  of  water.     Invert  over 
this  another  tumbler  and  seal  it  around  the  edge.     Ar- 
range two  tumblers  thus  and  place  one  in  sunshine  and 
the  other  in  the  shade. 

11.  What  do  you  observe  in  the  two  inverted  tumblers  ? 
Note  the  effect  of  different  temperatures. 

12.  What  does  this  experiment   show  you  about   the 
roots  of  a  plant  ?    About  the  stem  ?     About  the  leaves  ? 

13.  Prepare  another  plant  in  the  same  way  but  use  a 
cork  instead  of  the  cardboard  (the  inverted  tumbler  not 
being   needed).     Dry  the  plant  and  weigh  it.     Suspend 
the  roots  in  a  small  bottle  of  water.     Bore  a  hole  through 


June]  BOTANY.  4°5 

the  cork,  and  then  cut  into  it  a  lengthwise  slit  from  the 
side,  through  which  the  stem  may  be  passed  without 
injury  to  the  root.  Seal  the  bottle  tightly  and  weigh 
carefully.  Place  in  the  sunshine  for  two  hours  and 
weigh  again. 

14.  Can  you  notice  change  in  weight  ?     How  do  you 
account  for  it  ? 

15.  Place    it  for  the   same  length   of   time  in  a  dark 
closet  and  weigh  again  ;  what  is  the  result  ? 

16.  Compare  the  amount  of  change  during  the  day  with 
that  during  the  night. 

17.  Compare  the  amount  of  change  during  a  cloudy 
day  with  that  during  one  of  sunshine. 

1 8.  To  what  part  of  the  plant  is  this  passage  of  water 
chiefly  due  ?     Prepare  another  plant  in  the  same  way,  but 
remove  the  leaves.    Also  another  plant  with  the  stem  cut 
off  above  the  roots  ;  which  bottle  loses  most  in  weight  ? 

19.  Estimate  the  square' inches  of  leaf  area  of  one  of 
your  plants.     Count  the  leaves  on  a  branch  of  the  tree 
you  have  selected  for  study  and   estimate  its  entire  leaf 
surface.     How  much  water  could  it,  under  the  same  con- 
ditions, lift  in  one  day  ? 

20.  When  done  with  the  foregoing  experiments,  remove 
the    plant    and  carefully  remove  the  adhering  wax  and 
water  and  weigh  it  ;  has  the  plant  lost  or  gained  since 
you  prepared  it  ?     If  scales  are  not  convenient,  ask  any 
druggist  or  grocer  to  do  the  weighing  for  you. 

21.  The  passage  of  water  through  the  plant  is  called 
transpiration.     What  conditions  outside  the  plant  do  you 
find   most    favorable  for  it  ?     What  is  the  chief  cause  ? 
What  parts  of  the  plant  promote  it  ? 

22.  Fill  a  good  sized  test  tube  with  water  and  immerse 
in  it  a  small  stem  with  the  leaves  of  some  water  plant ; 


4°6  NATURE   STUDY.  [June 

place  in  the  sunshine  and  observe  closely.     Are  there  any 
signs  of  plant  action  ? 

23.  Remove  to  the  shade  ;  does  it  affect  the  action  ? 
If  possible  try  different  temperatures. 

24.  Use  boiled  water  ;  any  change  in  the  action  ? 

25.  Blow  the  breath  into  the  water  by  means  of  a  small 
tube  ;  can  you  notice  any  effect  ? 

26.  What  is  it  likely  the  water  must  contain,  judging 
from  the  above  experiments,  in  order  that  plant  action 
may  take  place  ? 

27.  By  placing  plants  and  leaves  of  different  kinds  in  a 
similar  manner  in  small  bottles  of  water,  try  to  collect 
some  of  the  gas  given  off  and  test  it  to  find  out  what  it  is. 
(See  Chemistry  for  preceding  months.) 

LEAVES. 

1.  On  what  part  of  the  tree  are  the  leaves  most  vigor- 
ous ?     Where  least  so  ? 

2.  On  what  part  of  the  branch  are  they  most  thrifty  ? 
Can  you  account  for  this  ? 

3.  Do  you  observe  any  regularity  in  the  arrangement 
of  leaves?     Can  you  account  for  it?     Is  there  any  con- 
stant relation  between  the  distance  the  leaves  are  apart 
and  the  size  of  the  leaf  ?     Compare  different  plants. 

4.  Are    they   arranged   equally   on    all    sides  of  the 
branch  ?     Does  their  arrangement  depend  in   any  way 
upon   the  direction  that  the  branch  grows?     Compare 
different  kinds  of  trees. 

5.  How  many  ranks  or  distinct  rows  of  leaves  can  you 
count  upon  your  twigs  ?     Wind  a  string  around  the  twig 
across  the  nodes  ;    how  many  times  does  it  pass  around 
the  twig  until  it  crosses  a  bud  over  the  one  started  with  ? 
How  many  ranks  are  crossed  in  reaching  this  point  ? 


June]  BOTANY.  407 

6.  The  ranking  arrangement  is  expressed  by  a  fraction 
whose  numerator  is  the  number  of  times  the  string  passes 
round  the  stick,  as  suggested  in  (5 ),  and  whose  denominator 
expresses  the  number  of  ranks. 

7.  What  is  the  size  of  the  angle  between  any  two  ranks  ? 
What  part  of  the  entire  circumference  is  it  ?     Compare 
with  the   fraction  found  in  (6).     The  size  of  the  angle 
between     two   successive    ranks   is   called     the    angular 
divergence  of  the  leaves.     Study  the  twigs  on  a  number 
of  different  trees  and  determine  the  number  of  ranks, 
angular  divergence,  etc. 

8.  Can   you  see  any   reason   why  the   leaves   of   any 
particular  kind  of  tree  take  the  shape  they  have  ? 

9.  Why  should  they  all  be  approximately  the  same  shape 
on  the  same  tree  ? 

10.  Can  you  find  any  two  of  exactly  the  same  shape  ? 
What  is  the  cause  of  the  variations  noticed  ? 

n.  Of   what   advantage   is   the   petiole,  /.  e.,  the    leaf 
stalk  ?     Such  leaves  are  said  to  be  petiolate. 

12.  Compare  a  plant  with  petiolate  leaves  with  one  that 
has  sessile  leaves,  i.e.,  those  without  foot  stalks  ;  can  you 
see  any  advantage  to  the  plant  in  the  sessile  leaf  ? 

13.  Note  the  two  common  varieties  of  netted  venation, 
the  pinnately-veined,   i.e.,    those   having   a   mid    rib  with 
diverging    veins,    and   palmately-veined,    or  those    having 
several  ribs  of  equal  size  radiating  from  a  common  point. 

14.  In  the  pinnate  leaf  do  you  find  both  sides  alike  in 
any  specimen  ?     What  causes  the  difference  ?     Note  the 
relation  of  one  leaf  to  another  and  to  the  branch  that 
bears  it. 

15.  Can  you  find  any  leaves  that  appear  to  be  transitional 
between  the  two  leading  types  ? 

1 6.  Note  the  leaves  borne  by  the  ash  tree  or  locust  tree  ; 


408  NATURE   STUDY.  [June 

these  are  compound  leaves.  Also  the  leaves  of  the 
poison  ivy,  or  Virginia  creeper  ;  compare  these  two  types 
of  compound  leaves  with  the  two  classes  of  simple  leaves. 
The  ash  leaf  hpinnately  compound  axi&  the  Virginia  creeper 
is  palmately  compound.  Can  you  find  intermediate  forms 
between  compound  and  simple  leaves  ? 

17.  What  is  the  real  difference  between  the  pinnate 
and  the  palmate  type  of  leaves  ? 

1 8.  Compare  the  venation  of  the  above  mentioned  leaves 
with  that  of  grass  blades,  and  flags,  and  all  lilies  ;  what 
difference   do  you  find  ?     The  latter  are  parallel-veined 
leaves. 

19.  Which  kind  of  plants  are  most  numerous,  those  with 
netted  or  parallel  veined  leaves  ? 

20.  What  kinds  of  seeds  produce  those  plants  that  bear 
netted  veined  leaves  ?     (See  Botany  for  April.)     Do  you 
find  any  exceptions  ? 

21.  What  kind  of  seeds  produce  plants  with  parallel- 
veined  leaves  ?     Look  for  exceptions. 

22.  Compare  the  stem  of  a  woody  plant,  as  the  ash,  maple, 
or  oak,  with  a  stalk  of  corn  ;  how  is  the  new  material  which 
goes  to  thicken  the  stem  added  in  each  ?     Compare  the 
leaves  of  the  woody  plants  mentioned  with  those  of  the 
corn.     Compare  the  seeds  from  which  they  grow. 

23.  Carefully  remove  the  bark  from  any  twig  or  branch 
that  is  alive  and  note  the  different  layers  ;  compare  with 
what   you    observed   in    early    spring.     (See    Botany  for 
March.) 

24.  Can  you  tell  why  the  bark  has  become  more  loosely 
attached  to  the  wood  ?     Is  it  entirely  separated  ? 

25.  Scrape  up  a  little  of  the  sappy  layer  and  rub  be- 
tween the  fingers ;  is  it  pure  water  ?     Compare  with  the 


June]  BOTANY.  4°9 

watery    substance  which   you  find  in  young  leaves  and 
twigs. 

26.  This  sappy  layer  is  called  the  cambium,  or  the  cam- 
bium layer  ;  can  you  see  what  it  does  for  the  plant  ?     You 
must  watch  the  growth  carefully  before  trying  to  answer 
this  question. 

27.  Can    you    find    a   cambium    layer    in    the    corn- 
stalk ? 

28.  Plants  whose  stems  grow  in  thickness  by  means  of  the 
cambium  layer  are  called  exogens,  and  are  said  to  be  ex- 
ogenous.   Exogen  means  growing  on   the  outside.     Plants 
whose   stems   thicken  by  general  growth  throughout  the 
stem  are  called  endogens,  and  are  said  to  be  endogenous. 
Endogen  means  growing  within. 

29.  Which  are  more  abundant  in  our  latitude,  exogens  or 
endogens?     Compare  the  two  kinds  as  to  their  buds  and 
branches.     Compare  the  locations  where  the  two  classes 
of  plants  are  found. 

30.  Look  in  pictures  of  tropical  scenes  for  endogenous 
plants,  conspicuous  among  them  being  the  palms.     Note 
the  branches.     In  some  kinds  the  whole  life  of  the  tree  is 
dependent  upon  the  life  of  the  terminal  bud  :  when  that  is 
destroyed  the  plant  dies. 

31.  Compare  the  flowers  of  the  parallel-veined  leaved 
plants  with  those  having  netted-veined  ;  what  is  the  ruling 
number  in  the  parts  of  each  whorl  in  the  former  ?     (See 
Botany  for  May.) 

32.  What  contrasts  do  you  observe  between  exogens 
and  endogens  ?     Compare  as  to  seeds,  stems,  leaves,  and 
flowers.     Have  you  found  any  plants  that  form  exceptions 
to  the  rule  ? 


NATURE  STUDY.  [June 


THE  GRASSES. 

The  best  material,  perhaps,  which  can  be  used  in  the 
beginning  of  the  study  of  grasses  is  wheat  or  rye  in  blos- 
som. This  may  be  obtained  almost  anywhere  during 
this  month. 

1.  What  peculiarities  distinguish  rye  from  other  plants 
studied  thus  far  ? 

2.  Can    you    see   a    reason    why   its   flowers   are  not 
colored?     Have  they  any  odor  ?     Have  they  nectar  ? 

3.  Do  insects  visit  these  flowers  ?     Why  ? 

4.  What  is  most  conspicuous  about  the  flower  ?     Com- 
pare in  this  respect  with   other   flowers  previously   ex- 
amined.    Can  you  see  a  reason  for  the  difference  ? 

5.  Compare  the  stem  in  point  of  size  with  that  of  other 
plants.     How  does  it  compare  in  strength?     In  weight  ? 
Is  the  slender  stem  of  any  advantage  to  the  plant  ? 

6.  The  hollow  jointed  form  of  stem  is  called  a  culm. 
The  form  of  inflorescence  is  a  compound  spike.     The  dif- 
ferent parts  borne  upon  the  axis  of  the  flower-cluster  are 
called  spikelets. 

7-  The  outer  husks  in  the  spikelet  are  called  the  upper 
and  lower  glumes.  Inside  of  these,  look  for  the  floral 
whorls.  The  chaffy  scales  are  the  palets  —  inner  and  outer. 
At  the  base  of  these  look  for  two  minute  scales  called 
lodicules.  What  whorl  of  the  flower  do  they  represent  ? 
Note  the  feathery  (plumose)  stigmas. 

8.  Compare  the  amount  of  pollen  produced  by  grains 
and  grasses  with  that  of  other  plants  ;  can  you  see  why 
a  great  quantity  is  needed  ? 

9.  Compare  some   of   the   common   grasses  with   the 
grains  that  have  been  examined  ;  do   the   parts   corre- 
spond ? 


June]  BOTANY.  411 

10.  What  resemblances  and  differences  do  you  find  be- 
tween wheat,  rye,  oats,  etc.,   and   Indian  corn  ?     What 
constitutes  the  tassel  in  corn  ?     What  is  it  that  forms  the 
ear? 

11.  When  are  the  different  cereals  planted  or  sown  ? 
How  long  does  it  take  them  to  mature  ? 


(Musics* 


ELECTRICITY. 

There  is  no  more  interesting  department  of  physics 
than  that  of  electricity,  and  certainly  there  is  no  one  of 
greater  practical  importance  at  the  present  day.  Owing 
to  the  fact,  however,  that  to  get  much  out  of  the  subject 
in  an  elementary  course  that  is  of  practical  value,  con- 
siderable apparatus  of  some  complexity  is  required,  not 
much  beyond  a  few  simple  experiments,  showing  some- 
thing of  the  nature  of  electricity,  can  be  attempted  in  the 
common  schools  at  present.  As  an  offset  to  the  difficulties 
in  the  way  regarding  apparatus,  there  is  the  deep  interest 
which  pupils  almost  invariably  show  in  the  subject,  which 
will  impel  them  to  greater  efforts  in  the  preparation  of 

needed  materials. 

•  • 

MAGNETISM   AND   FRICTIONAL   ELECTRICITY. 

1.  Dip  a  common  magnet  (see  Physics  for  September) 
into  a  pile  of  iron  filings  or  small  carpet  tacks ;  will  they 
stick  equally  well  all  round  the  bend  in  the  magnet  ? 

2.  Magnetize  a  large  knitting  needle,  as  directed  in  Sep- 
tember, and  test  it  with  iron  filings.     Enough  filings  may 
be  obtained  by  filing  a  piece  of  soft  iron  or  a  nail  for  a  few 
minutes.     Place  them  on  a  sheet  of  white  paper.     Do  the 
filings  adhere  equally  well  along  its  entire  length  ?     Break 
the  needle  in  the  middle  and  try  again. 

3.  A  straight  magnet  like  the  knitting  needle  is  called 

4T2 


June]  PHYSICS.  ^4*3 

a  bar  magnet  ;  one  that  is  bent,  like  those  used  in  Sep- 
tember, is  a  horseshoe  magnet.  In  what  respect  are  the 
two  kinds  alike  in  the  attraction  of  filings  ? 

4.  Procure  some  pith,  such  as  may  be  found  in  an  elder 
or  cornstalk  and  thoroughly  dry  it.     Make  two  small  balls 
from  it  about  the  size  of  a  pea,  and  suspend  them  an  inch 
apart  by    a  fine    silk    thread,  eight   or  ten   inches    long. 
Fasten  the  upper  ends  of  the  threads  to  a  wooden  sup- 
port by  means  of  a  drop  of  sealing  wax. 

5.  Rub  a  stick  of  sealing  wax  briskly  upon  the  sleeve 
or  with  a  dry  piece  of  flannel  for  a  minute,  and  then  bring 
the  wax  near  the  balls.     At  what  distance  do  you  notice 
the  influence  of  the  wax  upon  the  balls  ? 

6.  What  happens  after  they  have  clung  to  the  wax  for 
a  short  time  ?     After  they  have  left  the  wax  rub  it  again 
and  bring  it  near  ;  it  is  now  said  to  repel  the  balls,  while 
a  moment  before  it  attracted  them. 

7.  Rub  a  glass  tube  or  rod  instead  of  the  sealing  wax 
and  bring  it  near  the  balls  ;  are  they  attracted  or  repelled  ? 

8.  When  they  are  repelled  from  the  rod,  again  bring  the 
sealing  wax  near  ;  are  they  attracted  or  repelled  ?     When 
tlmy  are  repelled  from  the  sealing  wax,  bring  the  glass  rod 
near  ;  are  they  attracted  or  repelled  ? 

9.  Instead  of  the   sealing  wax,  use  a  gutta-percha  pen- 
holder or  comb  ;  do  the  balls  behave  toward  it  as  they  do 
toward  the  wax,  or  as  they  do  toward  the  glass  ? 

10.  Bring  the  wax,  the  glass  tube,  and  the  comb,  after 
rubbing  vigorously,  close  to  some  bits  of  paper  or  cotton  ; 
are  they  attracted  and  repelled  in  the  same  way  ? 

IT.  Bring  the  excited  wax  and  glass  near  your  magnetic 
needle  ;  is  there  any  effect.?  Does  it  repel  either  end  ? 

12.  Rubbing  the  glass  and  wax  produced  electricity  by 
friction.  When  the  pith  balls  flew  to  either  they  re- 


4H  NATURE   STUDY.  [June 

mained  until  charged.     The  silk  thread  prevents  this  from 
escaping  very  rapidly,  if  the  air  is  dry. 

13.  That    received    from   the    wax    is   called    negative 
electricity  ;  that  received  from  the  glass  is  called  positive 
electricity. 

14.  Rub  both  the  glass  and  the  wax  and  bring  them  close 
to  the  pith  ball  on  opposite  sides  ;  what  takes  place  ? 

15.  What  do  you  notice  when  the  ball  becomes  charged 
with  negative  electricity?     What  happens  when  it  becomes 
charged  with  positive  electricity  ? 

16.  When  two  bodies  are  charged  with  the  same  kind  of 
electricity  how  do  they  behave  toward  each  other  ?     How 
is  it  when  they  are  charged  with  the  opposite  kinds  of  elec- 
tricity ? 

17.  Any    contrivance    like   the   pith   ball  which    will 
show    the    presence   of   electricity    is    called  an    electro- 
scope.    Use   it   to   test    whether   electricity  may  be  ob- 
tained by  rubbing  silk,  paper,  and   other  substances. 

18.  Charge  the  pith  ball  with  electricity  from  the  glass 
tube,  as  above  described.     Now  bring  near  to  it  a  piece 
of  silk  ribbon  which  has  been  briskly  rubbed ;  can  you 
tell  whether  the  silk  is  charged  with  negative  or  positive 
electricity  ?     How  may  the  electroscope  be  used  to  tell 
the  kind  of  electricity  developed  in  any  substance? 

19.  By  rubbing  a  stick  of  sealing  v/ax  vigorously  for 
some  time  with  dry  flannel,  a  slight  crackling  sound  will 
be  heard  when  it  is   brought   near  the  knuckle  ;  in  the 
dark  a  tiny  spark  may  be  seen.    The  same  kind  of  sparks 
may  be  seen  when  a  cat's  back  is  rubbed,  and  the  same 
crackling  sound  will  be  heard. 

20.  Can   you  develop  electricity  by  rubbing  an  iron 
rod  as  was  done  with  the  glass  and  sealing  wax  ? 

21.  Wrap   one  end  of  the    iron    rod  well  with   a  silk 


June]  PHYSICS.  4J5 

handkerchief,  rub  thoroughly,  and  test  with  the  pith  ball 
for  electricity  ;  anything  which  prevents  an  object  from 
losing  its  electricity  is  called  an  insulator. 

22.  Rub  one  end  of  a  long  stick  of  wax  and  bring  the 
other  end  close  to  the  pith  ball  or  a  bit  of  cotton  ;  does  it 
show  the  presence  of  electricity  ? 

23.  In  the  case  of  the  iron,  in  the  first  instance,  the 
electricity  passed  over  the  iron  to  the  hand  and  through 
the  body  to  the  ground  as  fast  as  formed,  but  not  so  with 
the  sealing  wax.     Any  substance  like  the  wax  in  this  re- 
spect is  called  a  non-conductor;  when  like  the  iron,  it  is 
called  a  conductor. 

24.  Lightning  is  a  large  spark  of   electricity  passing 
from  one  cloud  to  another  cr  from  a  cloud  to  the  earth  ; 
can  you  see  a  use  for  lightning  rods  ?     Why  are  they  usu- 
ally fastened  to  the  roof  and  sides  of  the  house  by  being 
passed  through  glass  rings  ?     What    is   the  proper  name 
for  the  rings  ? 

VOLTAIC   ELECTRICITY. 

1.  Place  a  piece  of  zinc,  about  three  inches  long  and 
two  inches  wide,  in  a  glass  of  water  to  which  half  a  tea- 
spoonful  of  sulphuric  acid  has  been  added  ;  what  takes 
place?      Is  it  a  chemical  or  physical  change  ? 

2.  Place  in  the  same  vessel  a  strip  of  copper  of  same 
size.     Punch  a  small  hole  through  the  ends  of  the  copper 
and  zinc  not  immersed,  and  pass  through  each  a  small 
copper  wire  a  foot  long.     Bend  the    outer  ends  of  the 
copper  and  zinc  over  the  edge  of  the  tumbler  so  that  they 
will  remain  in  place  without  touching. 

3.  Put,  first,  the  end  of  the  copper  wire  from  the  zinc  in 
the  mouth,  and  then  that  from  the  copper  ;  is  there  any 
taste  noticeable  ? 


41 6  NATURE   STUDY.  [June 

4.  Place  the  ends  of  both  wires  in  the  mouth  without 
allowing  them  to   touch  ;  do  you  note   any  difference  in 
taste  ?     Note  what  is  taking  place  in  the  tumbler. 

5.  Procure  several  feet  of  insulated  copper  wire,  such 
as  is  used  for  door-bells,  and  wind  two  or  three  feet  of 
it  lengthwise  around  a  block,  two  inches  long  and   one 
inch  wide,  in  an  even  coil.     Place  this  coil  beneath  your 
magnetic  needle  and  close  to  it,  with  the  wires  running 
parallel  with  the  needle. 

6.  Bring  the  wire  from  the  copper  strip   into  contact 
with  one  end  of  the   wire  in  the   coil,  and,  watching  the 
needle  sharply,  place  the  wire  from  the  zinc   in  contact 
with  the  other  end  ;  does  the  needle  give  any  evidence 
of  disturbance  ?     Which  way  does  it  turn? 

7.  Touch  the  ends  of  the  coil  with  the  opposite  wires 
from  the  copper  and  zinc  ;  what  changes  in  the  behavior 
of  the  needle  ? 

8.  Such  a  coil  with  a  needle  attached  is  called  a  galvan- 
ometer. 

9.  Another  form  easily  made  may  be  constructed  thus. 
Take  a  block  of  pine  wood  five  inches  square  and    two 
inches  thick.     Saw  each  corner  off,  making  it  octagonal  in 
shape.     Cut  a  hole  through  the   middle   about   two  and 
one-half  or  three  inches  in  diameter.     Within  the  ring  of 
wood  thus  formed  suspend  a  magnetized  sewing  needle 
(see  Physics   for  September)  by  a  single   fiber  of  a  silk 
thread.     The  thread  is  easily  attached  to  the  wood  by  a 
drop  of  sealing  wax.     Wrap  around  the  ring  on  the  out- 
side, smoothly  and  evenly,  eight  or  ten  turns  of  the  in- 
sulated copper  wire.     A  groove  should  be  cut  on  the  un- 
der side  of  the  ring  to  receive  the  coil  of  wire  so  that  the 
ring  may  be  fastened  to  a  block  about  the  same  size  for  a 
base.     No  iron  should  be  used  in  the  construction  of  this 


June]  PHYSICS.  4*7 

instrument.  Why  ?  It  is  more  convenient  to  have  the 
ends  of  the  wire  in  the  coil  near  each  other.  Place  the 
ring  in  such  a  position  that  the  wire  in  the  coil  will 
be  parallel  with  the  needle  when  it  points  north  and  south. 
Bring  the  wires  from  the  copper  and  zinc  strips  in  con- 
tact with  the  ends  of  the  coil  and  observe  the  needle. 
Change  the  wires  to  the  opposite  ends  of  the  coil  and 
note  the  difference. 

10.  The  needle  is  turned,  deflected,  by  what  is  called 
a  current  of  electricity  which  is  generated  by  the  action 
of  the  acid  and  water  on  the  zinc  and  copper.  Anything 
which  will  thus  generate  electricity  by  chemical  action  is 
a  battery. 

n.  The  direction  of  the  current  is  also  determined  from 
observation  of  the  needle.  If  the  current  passes  from 
north  to  south  above  the  needle,  or  from  south  to  north  below 
it,  the  north  pole  of  the  needle  is  deflected  toward  the 
east.  If  the  current  passes  from  north  to  south  below  the 
needle,  or  from  south  to  north  above  it,  the  north  pole  of 
the  needle  is  deflected  toward  the  west.  Do  you  see  any 
way  by  which  the  needle  may  indicate  the  strength  of  the 
current  ? 

12.  Another  way  to  make  a  battery  is  as  follows  :  pro- 
cure about  fifteen  copper  cents  and  an  equal  number  of 
pieces  of  sheet  zinc,  cut  in  squares,  the  edge  of  each  be- 
ing equal  to  the  diameter  of  the  cent.  Cut,  also,  thirty 
squares  of  cloth  or  blotting  paper  of  same  size  of  the 
zinc.  Of  these  make  a  pile  :  first  a  piece  of  zinc,  then  a 
square  of  cloth,  then  a  cent,  then  a  square  of  cloth,  then 
zinc,  and  so  on.  When  finished,  bind  them  together 
tightly  with  a  strong  cord.  Two  copper  wires  must  either 
be  soldered,  one  to  the  zinc  and  one  to  the  copper  at  the 
opposite  end,  or  else  tied  tightly  against  the  two  pieces. 


NATURE  STUDY.  [June 

This  is  called  a  Voltaic  pile,  from  a  man  named  Volta, 
an  Italian,  who  first  used  this  means  of  producing  elec- 
tricity. 

13.  The  acid  and  water  may  be  used  with  this  bat- 
tery, but  a  better  fluid  may  be  made  as  follows  for  a 
few  cents  :  Water,   one  pint  ;  bichromate  of  potash,  two 
ounces  ;  sulphuric  acid,  two  ounces.     Powder  the  bichro- 
mate and  dissolve  in  the  water  ;  afterward  add  the  acid 
in  a  fine  stream,  stirring  all  the  time,  and  allow  it  to 
cool.     When  the  battery  is  not  in  use  remove  the  pile 
and  rinse  thoroughly,  and  it  will  last  for  some  time. 

14.  Another  battery,  easily  and  cheaply  made,  and  which 
will  give  a  current  of  sufficient  strength  to  ring  a  door-bell, 
may  be  made  thus  :   Procure  two  sticks  of  carbon,  each 
about  eight  inches  long,  such  as  are  used  in  electric  lights, 
and  two   pieces  of  zinc  of  same  length,  and  about  one- 
fourth  of  an  inch  square.     Any  dealer  in  electrical  sup- 
plies can  furnish  them,  provided  with  binding  screw,  for 
ten  cents  each.     Cut  a  strip  of  wood  six  inches  long,  an 
inch  wide,  and  half  an  inch   thick.     One  inch  from  each 
end  bore  a  hole  sufficiently  large  to  let  the  carbon  sticks 
pass  through,  and  fasten  a  carbon  in   each  one,  allowing 
about  an  inch  to  project   above.     To  the  side  of  the 
stick  next  the  carbons  bind  or  clamp  the  zincs.     Connect 
the  zinc  at  one  end  with  the  carbon,  at  the  other  with  a 
wire.     Attach  a  copper  wire  to  the  other  zinc  and  another 
one  to    the   other    carbon  for  the  poles  of  the   battery. 
Use  wide-mouthed  morphia  bottles  for  jars  for  the  bat- 
tery  fluid.     The   zincs    should   be   amalgamated    before 
using  by  first  washing  perfectly  clean,  using  a  little  dilute 
acid  if  necessary,   and  then   rubbing  them   with  a  little 
mercury  until  bright.     An  amalgamating  fluid    may  be 
made  thus  :  Mix  one  part  nitric  acid  and  three  parts  hy- 


June]  PHYSICS.  419 

drochloric  acid  by  measure  ;  to  about  one  pint  of  the 
mixture  add  an  ounce  of  mercury.  When  dissolved, 
clean  and  immerse  the  zincs  until  bright.  Keep  the  fluid 
in  a  glass-stoppered  bottle.  It  may  be  used  over  again 
as  long  as  the  mercury  lasts. 

15.  Test   the  battery  with  the  galvanometer.      Wrap 
a  wrought  nail  or  piece  of  soft  iron  wire  with  a  coil  of 
insulated  copper  wire.     Test  the  nail  or  wire  with  iron 
filings  for  magnetic  properties.     Connect  the  ends  of  the 
wire  in  the  coil  with   the  poles  of  the  battery,  and  test 
again  ;  what  result  ?     Break  connection,  /.  e.}  open  the 
circuit  and  note  the  effect  on  the  filings. 

16.  If  possible,  study  the  mechanism  of  an  electric  bell 
and  note  the  battery  connections.     The  nail  with  wire 
around  it,  described  in  (15),  is  called  an  electro-magnet. 
The  electric  bell  is  rung  by  means  of  an  electro-magnet 
which  is  rapidly  magnetized  and  as  quickly  demagnetized. 
How  is  this  accomplished  ? 

17.  In  how  many  ways  can  you  prove  the  presence  of 
the  electric  current  in  the  wires  ? 

1 8.  How  can  you  decide  as  to  its  direction  ?     Since 
the  needle  in  the  galvanometer  tends  to  place  itself  in   a 
position  at  right  angles  to  the  course  of  the  current  along 
the  wires,  can  you  from  that  fact  make  any  inference  as 
to  the  force    which    causes    the  needle  of  the   compass 
to  point  north  and  south  ? 

19.  How  can  you  test  the  strength  of  an  electric  cur- 
rent ? 


CHLORINE. 

The  study  of  this  gas  will  present  several  noteworthy 
contrasts  with  those  considered  in  the  preceding  months. 
The  materials  needed  are  cheap  and  easily  obtained. 
The  experiments  are  all  perfectly  safe,  but  to  avoid  some 
disagreeable  effects  on  breathing,  the  gas  should  be 
made  where  there  is  a  good  draught.  The  properties  of 
chlorine  are  interesting  and  useful. 

1.  Place  in  a   test  tube  half  an  inch  of  manganese 
dioxide    and    pour    upon   it  a   little    hydrochloric    acid. 
Warm   gently   over    the   alcohol   lamp.     What   evidence 
have  you  of  a  gas  being  formed  ?     Can  you  detect  any 
odor  ?      The  gas  formed  is  chlorine.      Symbol,  Cl. 

2.  Hold  in    the    tube    moist    strips   of  litmus    paper ; 
what  takes  place  ?     Moisten  pieces   of  calico  and  hold 
them  in  the  fumes.     Is  there  any  change  produced  if  the 
articles  are  not  moistened  ? 

3.  Place  a  few  small  crystals  of  potassium   chlorate  in 
a  test  tube,  add  hydrochloric  acid,  and  test  again  as  in  (2). 
Have  you  the  same  gas  formed  ? 

4.  Place  in  a  test  tube  a  small  quantity  of  manganese 
dioxide   mixed  with  an  equal  weight   of  common   salt. 
These   should  be  well  mixed  and  pulverized.     Mix  to- 
gether a  small   quantity   of  sulphuric    acid    and   water, 
equal  weights  of  each,  and  pour  upon  the  mixture  in  the 
tube.     Warm  gently  and  test  as  above  for  chlorine. 

5.  Is  chlorine  heavier  or  lighter  than  air?    To  collect 


June]  CHEMISTRY.  421 

this  gas  fit  the  test  tube  with  a  cork  and  bent  tube  as  in 
former  experiments,  and  so  arrange  the  latter  that  it  may 
pass  through  a  piece  of  cardboard  to  the  bottom  of  the 
collecting  jar,  the  cardboard  being  used  as  a  lid  for  the 
jar.  Why  is  it  possible  to  collect  the  gas  in  this  manner? 
Could  you  collect  it  as  you  did  oxygen  or  hydrogen  ? 

6.  Moisten  a  piece  of  paper  with  turpentine,  a  little 
warm,  and  hang  it  in  the  vessel  of  chlorine  ;  does  it  re- 
call any  previous  experiment  ? 

7.  In  a  fresh  jar  of  chlorine  insert  a  candle  or  lighted 
taper  ;  does  it  burn  ?     Does  it  support  combustion  ? 

8.  Place  in  a  fruit  jar  a   tablespoonful  of  sulphuric 
acid.     Sprinkle  into  this  a  tablespoonful  of  bleaching 
powder,  or  chloride  of  lime,  as  it  is  also  called.     Cover 
the  jar  with  a  plate  or  piece  of  glass. 

9.  Moisten  some  rose  leaves  and  hang  them    in  the 
jar  ;    what  change  do  you  notice  ? 

10.  Write  a  sentence  upon  a  piece  of  paper,  and,  after 
moistening  it,  hang  it  within  the  jar.     Try  a  moistened 
bit  of  paper  with  printing  upon  it. 

11.  Chlorine    has   a   strong  affinity  for  hydrogen.     In 
the  experiment  with  turpentine  it   united  with  the  hydro- 
gen and  left  the  carbon.     Printers'  ink  being  made  of 
carbon,  the  chlorine  does  not  affect  it. 

12.  Chlorine  is  now  much   used   in    bleaching  cloth, 
paper  pulp,  etc.     It  is  prepared  in  the  form  of  the  bleach- 
ing powder  that  may  be  bought  at  the  shops. 

13.  Bleaching  powder  is  also  used  as  a  disinfectant  in 
sick  rooms  and  other  places.     Exposed  to  the  air  the  Cl 
is  set  free  and  unites  with  the  hydrogen  of  the  offensive 
substances,  breaking  them   up.     The  process  is  hastened 
by  the  addition  of  a  little  dilute  sulphuric  acid.     It  is 
much  used  in  hospitals. 


flDeteorologp. 

The  meteorological  influences  of  this  month  are  usu- 
ally benign.  If  the  past  month  has  supplied  a  liberal 
amount  of  moisture,  the  warm  sunshine,  now  almost 
assured,  will  produce  most  wonderful  results. 

1.  How  many  thunder  showers  have  you  noticed  dur- 
ing the  past  two  months  ? 

2.  From  what  direction  do  they  usually  come  ? 

3.  In  what  part  of  the  day  have  most  of  them  occurred  ? 

4.  What  is  the  ratio  of  rains  without  thunder  to  those 
with  it  ? 

5.  Is-  there  any  uniformity  in  their  effect  upon  the 
temperature  ? 

6.  How  long  do  thunder  storms  usually  last  ? 

7.  Have  any  of  the  storms   been    accompanied   with 
hail  ?     What    was   the   effect    upon     the    temperature  ? 
Examine  a  hailstone. 

8.  Has  the  prevailing  wind  been  cool  or  warm  ?    What 
is  its  direction  ? 

9.  What  wind  accompanies  a  clearing  sky  ?     A  cloudy 
sky  ?     The  heaviest  rains  ? 

10.  What    is   the    rate   of    change   in     temperature  ? 
Compare  with  May  and  April. 

11.  Are  there  any  fogs  this  month?     When  are  they 
formed  ? 

12.  Have  you  noticed  any  frosts  this  month  ?     Any 
dews  ?     Any  nights  with  neither  frost    nor  dew  ?     Can 
you  explain  the  latter  ? 

422 


June]  METEOROLOGY.  423 

13.  Which  are  cooler,  clear  or  cloudy  days  ?     Why  ? 

14.  Which  are  cooler,  clear  or  cloudy  nights  ?     Why  ? 

15.  Compare    the   barometric    record    with    that    for 
May. 

1 6.  Use  the  following  suggestions  for  a  summary  for 
the  year  :  What  month  had  the  greatest  number  of  rainy 
days  ?     The  largest  number  of  clear  days  ? 

17.  Which  was  the  warmest  month  for  the  year  ? 

1 8.  Which  was  the  coldest  month  ?     How  far  apart  are 
these  extremes  ? 

19.  Which  season  has  the  most  cloudy  days  ?     Can  you 
explain   this  ? 

20.  Do  the  rains  of  summer  occur  mostly  in  the  fore- 
noon or  afternoon  ?     In  daytime  or  night  ? 

STUDY  OF  THE   WEATHER  BUREAU   MAPS. 

21.  Compare  the  isotherm  60  degrees  this  month  with 
its  course  and    direction  in   May  and  April.     Can  you 
account  for  any  variation. 

22.  In   what  quarter  of  the  country  have  there  been 
the  most   Low  Areas  ?     In  what  quarter  has  there  been 
the  heaviest  rainfall  ? 

23.  Are  the  isotherms  more  or  less  regular  in   their 
course  this  month  than  last  ? 

24.  Compare  the  temperature  of  the  plain  between  the 
two  great  mountain  systems  with  that  indicated  along  the 
coast.     Can    you    see    any   reason    for    any   differences 
noted  ? 

25.  Which   isotherms    vary   most   from    their   normal 
course,  those  in  the  north  or  in  the  south  ?     Why  ? 

26.  What  isotherm  this  month  crosses  where  you  live  ? 
Compare  with  last  month, 


424  NATURE   STUDY.  [June 

27.  Does  the  temperature  of  the  Low  and  High  Areas 
still  vary  as  in  the  preceding  months  ? 

28.  Where  is  the  region  of  lowest  temperature  in  the 
country  during  this  month  ?     Why  is  it  so  ? 

29.  Where  is  the  region  of  highest  temperature  ?    Can 
you  explain  ? 


astronomy 

In  this  month,  the  last  of  the  school  year,  as  much 
as  possible  should  be  done  by  way  of  comparison  with  the 
different  seasons.  At  this  time  another  mile  post  of  the 
year  is  reached  at  the  summer  solstice,  and  the  effects 
shouldjbe  traced  as  far  throughout  nature  as  the  children 
can  comprehend.  Children  naturally  seek  for  causes  of 
the  results  they  see  around  them,  and  it  is  the  principal 
duty  of  the  teacher  to  impress  them  with  the  fact  that 
the  immediate  causes  will  always  be  found  if  skill  and 
patience  are  observed  in  the  search.  It  too  often  happens 
that  teachers,  either  through  ignorance  or  neglect,  directly 
or  indirectly  impress  the  pupils  with  the  notion  that  the 
phenomena  of  nature  either  have  no  important  bearing 
upon  themselves,  or  that  they  happen  at  random,  with- 
out direct  cause.  In  either  case  the  result  is  a  grown  up 
man  or  woman  who  has  not  the  slightest  knowledge  of 
nature,  or  interest  in  the  very  things  about  him  on  which 
his  life  depends.  That  the  possibility  still  exists  for  the 
public  schools  to  produce  such  deformities  in  character 
is  a  fact  much  to  be  deprecated. 

1.  How  does  the  rate  and  direction  of  change  in  the 
noon  shadow  compare  with  that  in  May  ? 

2.  Compare  the   length  of  day  and  night  in  the  two 
months.     Is  the  rate  of  change  the  same  ? 

3.  When  is  the  greatest  variation  in  the  day's  length 
made,  at  morning  or  evening  ? 

4.  What  angle  do  the  sun's  rays  make  with  the  earth  the 

425 


426  NATURE   STUDY.  [June 

first  of  the  month  ?  What  is  the  greatest  angle  they  make 
during  the  month  ?  What  do  you  notice  about  the  length 
of  day  at  that  time  ?  June  twenty-first  is  called  the 
summer  solstice,  a  word  meaning  the  sun  standing  still. 
Consult  your  noon  marks  for  a  reason  for  this.  Can 
you  explain  why  the  sun  seems  to  move  slowly  at  this 
time  ? 

5.  At  the  same  date  note  the  points  on  the  horizon 
where  the  sun  rises  and  sets ;  how  far  have  they  moved 
since  March  ?     Since  December  ? 

6.  Why  are  the  days  and  nights  unequal  at  this  time  of 
year  ? 

7.  At  what    point  in   the  United    States  is  there  the 
greatest  inequality  in  day  and  night  ?     Where  are  they 
nearest  equal  ? 

8.  Compare  the  length  of  day  and  night  in  the  places 
found  in  (7)    with  that  of  the  same  places   in  Decem- 
ber ;  explain  why  the  case  appears  to  be  reversed  at  this 
time. 

9.  Is  there  a  corresponding  variation  between  places 
remote  from  each  other  but  on  the  same  parallel  ?     Can 
you  see  a  reason  for  this  ? 

10.  In  what  month  during  the  year   did   the  -shadow 
travel  farthest  along  the  shadow-stick  ?     In  which  the 
least? 

11.  Through  how  many  degrees  did  the  slant  of  the 
rays,   as   indicated    by    the   shadow,  travel   during   the 
year  ? 

12.  In  what  months  did  the  shadow  stand  at  the  same 
place  on  the  stick  ?     How  did  those  months  compare  as 
to  temperature  and  rainfall  ?     Explain  why  the  shadow 
stands  at  the  same  place,  and  why  the  effects  as  observed 
in  temperature  and  rainfall  are  different. 


June,  ASTRONOMY.  427 

13.  Can  you  now  explain  why  we  have  four  seasons  in 
a  year  ?    Is  it  the  same  all  over  the  earth  ?    Why  ? 

14.  At  what  date  was  the  lowest  temperature  reached 
this  year  ?     What  has  caused  the  gradual   rise  in  tem- 
perature since  then  ? 

15.  In  what  region  is  the  greatest  heat  during  the  year  ? 
Where  the  greatest  cold  ?     Why  ? 

1 6.  In  what  region  is  there  the  greatest  extremes  of  heat 
and  cold  ?     Why  ? 

17.  Compare  the  plant  and  animal  life,  including  man, 
in  the  three  regions  referred  to  in  (12)  and  (13) ;  in  which 
region  does  the  greater  amount  of  land  lie  ? 

18.  In  which  region  is  the  highest  civilization  to  i>e 
found  at  present  ?     Was  it  always  so  ? 

19.  Suppose  the  earth's  axis  were  inclined  less  than  it 
is,  or  not  at  all — how  would  it  affect  the  climate  of  the 
earth  ? 

20.  Suppose  it  were  inclined  more    than    it  is  ;   how 
would  the  three  regions  mentioned  in  (14)  be  affected  ? 
How  would  the  length  of  day  and  night  compare  with  that 
at  present  ? 

21.  Mercury  appears  June  fifth  in  1891  as  a  morning 
star ;  how  have  it  and  the  earth  changed  position  with 
respect  to  each  other  since  it  last  appeared  as  morning 
star  ?     (See  Astronomy  for  February.) 

22.  How  have  they  changed  relatively  since  Mercury 
appeared  as  evening  star  ?     (See  Astronomy  for  April.) 

23.  How  does   it   happen  that  Mercury  only  appears 
thus  periodically  as  morning  and  evening  star  ? 

24.  Additional   constellations  :     Cygnus  in  the   east  ; 
southeast,  Scorpio  ;  south,  the  Crow  and  the  Crater. 


WINDS. 

In  the  study  of  climate  as  suggested  in  many  of  the 
preceding  lessons,  it  has  been  necessary  to  refer  to  the 
winds  that  are  found  in  the  different  regions.  Taking 
these  together,  now,  it  will  be  seen  that  there  is  a  simi- 
larity between  those  of  certain  areas,  though  they  may  be 
remote  from  each  other.  Proceeding  from  such  general- 
ization, keeping  in  mind  what  has  been  learned  and 
illustrated  in  Physics,  pupils  may  in  time  be  led  to  trace 
the  winds  to  their  causes  and  thus  get  a  connected  view 
of  the  great  atmospheric  movements  of  the  earth.  In  the 
same  way,  also,  the  subject  of  ocean  currents  should  be 
developed.  Consult  a  good  physical  map  which  shows 
the  direction  of  the  winds  and  currents. 

1.  In  what  portions  of  the  globe  are  the  great  wind 
currents  the  least  turned  from  the  normal  course  ?     Com- 
pare the  land  and  water  areas. 

2.  Observe  the  direction  of  the  winds,  as  indicated  by 
the  arrows  on  the  map,  over  the  Pacific  Ocean  within  the 
tropics  ;  what  contrast  do  you    find  north  and  south  of 
the  equator  as  you  approach  the  tropics  ? 

3.  What  seems  to  be  the  prevailing  direction  at  the 
equator? 

4.  Trace    these    winds  around  the  globe  ;  where  are 
they  most  interrupted  ?     Compare  the  Atlantic  with  the 
Pacific  Ocean. 


June]  GEOGRAPHY.  429 

5.  Which   coasts  receive   these  winds  ?    This   belt  of 
westerly  moving  winds  is  called  the  Trade  Winds. 

6.  What  is  the  direction  of  the  winds  within  the  polar 
circles  ;  does  it  appear  to  be  uniform  ? 

7.  Which  coasts  of    the  continents  must  receive  the 
polar  winds?     How  are  these   winds  turned  from  their 
normal  course  ? 

8.  Note  the  direction  of  the  arrows  between  the  polar 
and  equatorial  winds  ;  follow  this  belt  around  the  globe 
and  notice  the  countries  included  in  it. 

9.  These  arrows  indicate  the  place  of  meeting  and  con- 
flict between   the  polar   and  equatorial  winds  ;  how   will 
this  interference  of  winds  affect  the  climate   of  this  re- 
gion ? 

10.  From  what  you  have  learned  heretofore  (see  Physics 
for  October)  can  you  see  what  the  great  disturbing  cause 
of  the  atmosphere  is  ? 

IT.  Under  what  conditions  would  there  be  no  atmos- 
pheric movements  ?  HOAV  do  existing  conditions  differ 
from  this  ? 

12.  What  movement  of  the  atmosphere  must  occur  un- 
der the  vertical  rays  of  the  sun  ?     What  is  the  shape  of  this 
area  under  the  vertical  rays  on  the  globe  ? 

13.  Is  the  position  of  this  belt  the  same  throughout  the 
year? 

14.  How  must  the  movement  of  the  air  in  the  belt  un- 
der the  vertical  rays  affect  the   air  lying  outside  of   it  ? 
How  far  north  and  south  will  the  disturbance  extend. 

15.  Will  the  air  that  comes  from  the  poles  be  a  surface 
or  an  upper  current  ? 

1 6.  What  will  determine  the  height  to  which  the  air 
under  the  vertical  rays  will  rise  ?     When  it  ceases  to  rise 
what  will  become  of  it  ?     What  forces  are  acting  upon  it  ? 


43°  NATURE  STUDY.  [June 

17.  How  will   its    elevation   change  as  it  moves  away 
from  the  equatorial  regions  ?     Why  ? 

18.  Can  you  now  account  for  the  line  of  conflict  no- 
ticed in  the   temperate  regions  ?     See  (9)  above.     This 
region  is  called  the  belt  of  Variable  Winds. 

19.  What  influences  will  tend   to  make  it  change    its 
position  during  the  year  ?     At  what  season  or  seasons  is 
the  wind  most   fickle  and    changeable   in  our   latitude  ? 
Where  are  the  rays  of  the  sun  vertical  then  ? 

20.  At   what  season  or  seasons    are    the  winds    least 
variable  ?     Where  is  the  belt  of  vertical  rays  at  such  times? 

21.  When  do  the  warm  winds  prevail  ?     Why  ?     The 
cold  winds  ?     Why  ? 

22.  The  winds   blowing  from  the  equatorial  regions 
toward  the  poles  are  called   the  Return    Trade    Winds. 
They  descend  to  the  surface  at  about  latitude  thirty  de- 
grees.    What  coasts  receive  these  winds  ?     What  is  their 
influence  upon   those  coasts  ?     Compare  the  eastern  and 
western  coasts  of  North   America  ;  also,   eastern  North 
America  and  western  Europe. 

23.  What  features  on  the  surface  of  the  globe  tend  to 
change  the  course  of  the  winds  ?     Study  the  course  of  the 
arrows  near  the  great   mountain    ranges.     Also  near   the 
coast  lines. 

24.  Can  you  see  how  the  presence  of  both  land  and 
water  tends  to  deflect  the   winds  from  the  course  they 
would  take  if  only  one  were  present  ? 

25.  Which  heats  more  rapidly  under  the  rays  of  the  sun, 
land  or  water  ?     Which  cools  more  rapidly  when  the  sun  is 
removed  ? 

26.  How  would  the  winds  be  deflected  near  a  continent 
or  ocean  in  winter  ?     In  summer  ?     In  the  daytime  ?     At 
night  ? 


June]  GEOGRAPHY.  431 

27.  Study  the  effect  which  the  earth's  rotation  must  have 
upon  the  atmosphere.     Turn  a  small  hand  globe  rapidly 
and    hold    a  thread  or  other  light  substance  near  it  ;  is 
there  any  evidence  that  the  air  surrounding  the  globe  is 
in  motion  ? 

28.  The  circumference  of  the  globe  is  twenty-five  thou- 
sand miles  and  it  makes  a  rotation  in  about  twenty-four 
hours  ;  what  is  the   rate  of  movement  of  a  point  at    the 
equator  ? 

29.  Would  a  point  in  our  latitude  have  the  same  speed  ? 
Why  ?     How  would  it  be  with  a  point  on  the  polar  circles  ? 
At  the  poles  ? 

30.  When  the  cold  air  starts  toward  the  equator  from 
the  poles  what  rotary  velocity  does  it  have  ?     As  it  moves 
into  regions  having  greater  rotary  velocity,  what  must  be 
the  effect  ? 

31.  Will    it   at  once   acquire   this  increased  velocity? 
What  must  happen,  then,  as  it  advances  toward  the  equa- 
tor ?     What  direction  will  it  have  in  the  northern  hemis- 
phere ?     In  the  southern  ? 

32.  When  the  air  in  the  upper  equatorial  regions  (see  16 
above)  starts  toward   the  poles,  what  will  be  its  rotary 
velocity  ?     As  it  advances  to  higher  latitude  how  will  this 
change  ?     Will  it  acquire  this  less  velocity  at  once  ?     What 
will  be  the  effect,  then,  upon  its  direction  ? 

33.  What  is  the  direction  of  the  return  trades  in  the  north- 
ern hemisphere  ?     In  the  southern  ?    Where  are  they  most 
interrupted  ? 

34.  What  causes  can  you    see   for  the  oceanic  move- 
ments ?     Are  they  in  any  way  dependent  upon  the  winds? 
Have  you  ever  seen  currents  started  on  the  surface  of  a 
pond  or  lake  by  the  wind  ? 

35.  Where  would  the  winds  have  the  strongest  effect  ? 


43 2  NATURE  STUDY.  [June 

36.  Note  the  width  and  direction  of  the  great  equatorial 
current  and  compare  with  the  winds  of  the  same  region. 

37.  Note  how  the  continents  affect  the  direction  of  this 
current  ;  would  the  earth's  rotation  affect  currents  of  water 
as  it  does  the  winds  ?     What  shores   receive    the  warm 
currents?     Which  receive  the  cold  currents  ? 

38.  Can  you  now  understand  why  Europe  and  North 
America  have  such  contrasts  in  climate  ?     Compare  the 
eastern  and  western  shores  of  North  and  South  America  ? 

39.  Is  the  character   of   a   nation    in    any   way  deter- 
mined by  the  winds  and  currents  that  sweep    upon  its 
shores  ? 

40.  What  nations  can  you  cite  as  illustrations  ? 


Geology 


SPRINGS  AND   WELLS. 

One  of  the  chief  features  of  a  country  which  will  always 
tell  for  or  against  it  is  the  springs  it  affords.  Abundance 
of  pure  spring  water  !  It  is  a  recommendation  for  a  place 
which  will  outweigh  many  very  disagreeable  things  in 
surface,  soil,  or  climate.  Its  mere  mention  brings  up  vis- 
ions of  health,  and  it  is  indeed  one  of  the  strongest  barriers 
against  pestilence  and  death.  From  earliest  times,  springs 
of  pure  water  have  been  objects  of  veneratiofi  to  man- 
kind, and  they  have  inspired  a  literature,  both  poetry  and 
prose,  that  can  be  appreciated  only  by  those  who,  having 
once  enjoyed  their  refreshing,  have  afterward  been  com- 
pelled to  depend  upon  the  warm,  turbid  supply  of  cities 
that  has,  too  often,  a  doubtful  origin.  Common  as  springs 
are  in  many  places,  they  are  always  interesting  to  the  stu- 
dent, and  their  ceaseless  flow,  year  after  year,  is  shrouded 
in  something  akin  to  mystery. 

1 .  What  becomes  of  the  rain  water  that  falls  to  the  earth  ? 
What  does  the  fog  that  rises  after  a  shower  mean  ?     What 
does  the  moistened  earth  after  the  water  has  disappeared 
from  the  surface  mean  ?    Where  does  the  water  come  from 
that  causes  a  stream  to  suddenly  overflow  its  banks  ? 

2.  Why  does  the  water  which  comes  down  in  a  shower 
stand  longer  on  the  surface  in  some  places  than  it  does  in 
others  ? 

3.  In  what  kind  of  ground  does  it  disappear  soonest  ? 

433 


434  NATURE   STUDY.  [June 

4.  What  determines  the  depth  to  which  it  must  sink  ? 

5.  Can  you  imagine  any  conditions  under  which  the  water 
would  start  to  flow  underground  ? 

6.  Why  is  it  that  water  stands  in  a  swamp  ?     Can  you 
think  why  it  neither  does  not  all  lie  on  the  surface  nor 
yet  sink  clear  below  it  ? 

7.  What  is  necessary  in  order  to  drain  a  swamp  ?     Can 
you  think  why  it  is  that  all  level  ground  is  not  swampy  ? 

8.  What  kind  of  ground  is  most  favorable  for  the  passage 
of  underground  waters  ? 

9.  Would  rocks  be  a  help  or  a  hindrance  to  it  ?     What 
part  in  spring  making  can  clay  perform  ? 

10.  When   the  surface   water  sinks  to  a   layer  of  clay 
or  rock  through  which  it  cannot  pass,  what  must  then  be- 
come of  it  ? 

11.  Wh^it  circumstances  would  favor   its  reappearance 
at  the  surface  ? 

12.  Can  you  think  why  it  is  that  it  appears  at  one  point 
instead  of  being  spread  out  ? 

13.  It  is  a  rule  that  those  springs  whose  flow  is  constant 
throughout  the  year  are  but  little  affected  by  wet  or  dry 
weather.    What  conditions  can  you  imagine  which  will  ac- 
count for  this  ? 

14.  What   conditions   must   exist  underground   which 
render  the  flow  from  a  spring  constant  and  uniform  in 
amount  ? 

15.  How  must  the  conditions  differ  in  those  springs 
which  flow  for  a  few  days  only,  after  a  heavy  rain  ? 

16.  There  are  springs  which  flow  for  a  time  and  then 
cease  for  a  while  ;  after  a  period  of  rest  the  flow  is  again 
resumed,  which  is  again  followed  by  a  rest.     These  are 
called  intermittent  springs.     Can  you  see  any  way  of  ac- 
counting for  such  a  flow  ? 


June]  GEOLOGY.  435 

17.  The  supposition  has  been  made  that  such  springs 
have  an  outlet  through  a  siphon-shaped  tube  ;  will  such 
a  supposition  account  for  the  facts  ?     Make  a  diagram  of 
such  an  underground  basin,  with  an  outlet  of  this  kind. 

1 8.  Since  rain  water  is   soft,  how  does  it  happen  that 
spring  water  is  frequently  hard  ?     What  kinds  of  rock  will 
make  hard  water  ? 

19.  What  would  be  the  result  if  the  soil  did  not  absorb 
large  quantities  of  water  when  it  rains  ?     Of  what  value, 
aside  from  drinking  purposes,  are  springs  ? 

20.  How  is  it  that  water  may  be  obtained  by  boring  a 
deep  hole  in  the  ground  ? 

21.  Sometimes,  after  boring  a  considerable  depth,  water 
is  obtained  and  it  rises  even  with,  and  often   above  the 
surface  ;  can  you  account  for  this  when  there  is  no  gas 
in  the  well  ?    What  must   be  the  character  of  such  an 
underground  basin  ? 

22.  Do  springs  ever  deposit  sediments  about  their  out- 
lets ?   Where  are  such  materials  obtained  ? 

23.  Which  would  be  more  likely  to  deposit  such  sedi- 
ments, cold  or  warm  springs  ?     Why  ? 

24.  The  light,  spongy  material  sometimes  found  about 
hot  springs  is  called  tufa. 

25.  Read  some  account  of  the  geysers  in  Iceland  and  of 
those  in  Yellowstone  Park. 


STUDY  OF  SOILS. 

Last  month  directions  were  given  for  rinding  out  the 
mechanical  constituents  of  soils.  It  will  now  be  interest- 
ing to  study  some  of  the  physical  properties  of  the  soils 
upon  which  their  value  to  plant  life  depends. 

1.  Have  you  noticed  any  difference  in  soils  as  to  the 
rate  at  which  they  allow  water  to  pass  through  them  ? 
To  test  this,  take  several  glass  tubes,  about  half  an  inch 
in  diameter  and  a  foot  long,  and  tie  over  one  end  a  piece 
of  linen.     Argand  lamp  chimneys  may  be  used  for  this 
purpose.     Fill  each  one  with  a  different  specimen  of  soil 
which  has  been  finely  powdered  and  well  dried.     Set  the 
tubes  upright  in  a  vessel  having  about  an  inch  of  water 
in  it,  and  note  the  rate  at  which  the  water  rises  in   the 
different  tubes.     Keep  the  water  at  a  constant  level  in 
the  pan  by  occasional  additions. 

2.  Which  soil  would  be  best  for  plants  ;  that  which 
allows  the  moisture  to  rise  rapidly  or  slowly  ?     Why  ? 

3.  Compare  the  sandy  with  clayey  soils. 

4.  The  amount  of  water  which  soil  can  hold  will  also 
affect  the  growth  of  plants.     Illustrate  the  different  capaci- 
ties  for  water   thus  :    Fold  two   filters  and  place   them 
loosely,  one  inside  the  other,  in  a  funnel.     Carefully  dry 
and  place  on  the  filter  an  ounce  of  finely  powdered  soil. 
Add  to  this  cold  water  by  drops  until  it  begins  to  trickle 

436 


June]  MINERALOGY.  437 

down  the  funnel  tube.  Continue  to  add  until  sure  that 
the  soil  is  perfectly  saturated  and  then  remove  the  filters 
to  a  piece  of  blotting  paper  or  a  cloth  which  will  absorb 
the  moisture  from  them.  Then  place  the  under  filter  in 
one  scale  pan  and  the  other  one,  with  the  soil  upon  it, 
upon  the  other,  and  balance  with  weights.  How  much 
heavier  is  it  now  than  the  dry  soil  ?  What  per  cent,  of 
its  weight  is  water  ? 

5.  To  get  an  idea  of  the  rate  of  evaporation  from  soil, 
place  the  filter  with  the  soil  on   it  in  the   open  air  and 
weigh  at  regular  intervals ;  what  per  cent,  does  it  lose  in 
an  hour  ?     Upon  what  conditions  will  the  rate  of  evapora- 
tion depend  ? 

6.  Compare  in  the  manner  above  described  loam,  sand, 
and  clay. 

7.  The  power  of  soils  to  absorb  water  from  the   atmos- 
phere may  be  illustrated  as  follows  :  Spread  out  evenly 
half  an  ounce  of  carefully  dried  soil  in  a  shallow  tin  box. 
The  lid  of  a  baking  powder  can  will  answer  the  purpose. 
Place  it  above  a  small  cup  of  water  (an  individual  salt  or 
butter  dish  may  be  used)  and  invert  ajar  or  large  tumbler 
over  both.     Seal  the  tumbler  around  the  edges  so  that 
it  may  be  air  tight.     After  standing  a  few  days  weigh  the 
soil  again  ;  has  it  gained  any  ?     To  what  is  the  increase 
due  ?     What  per  cent,  is  it  of  the  weight  of  dry  earth  ? 

8.  Soils  differ  in  their  powers  to  absorb  and  conduct 
the  heat  that  comes  from  the  sun,  and  they  may  be  tested 
in  this  respect  in  this  way  :  Fill  a  large  tomato  can  with 
finely  powdered  soil  ;  wrap  the  can  with  several  thick- 
nesses of  paper  and  set  it  in  the  sunshine.     After  a  little 
time  test   the  temperature   of    the   different   parts   with 
a  thermometer.     Compare  sand  with  loam  in   this  par- 
ticular. 


438  NATURE    STUDY.  [June 

9.  In  what  kinds  of  soils  do  plants  thrive  best  ?     In 
which  the  poorest  ? 

10.  What  are  the  qualities  of  good  soil  ?     What  are  its 
constituents  ?     (See  Mineralogy  for  May.) 

11.  How  does  abundance  of  rainfall  affect  the  soil  ? 

12.  Does  the  wind  in  any  way  affect  the  formation  of 
soil  ? 


INDEX. 


ABSORPTION,  109 

Acetic  acid,  formation  of,  46 

Acid,  effect  of ,  upon  marble,  117 

vEolian  harp,  study  of,  366 

Africa,  relief,  drainage,  climate, 
productions,  383 

Air,  230;  complemental,  390; 
elasticity  of,  190;  expansion 
of,  113;  impure,  311;  impuri- 
ties of ,  284;  movements,  155; 
pressure  of,  191,  195;  resid- 
ual, 310;  study  of,  189;  sup- 
plemental, 310;  tidal,  310 

Alburnum,  271 

Alcohol,  boiling  point,  84;  for- 
mation of,  46;  lamp,  how  to 
make  a  cheap,  115 

Almanac,  use  of,  50 

America,  see  North  and  South 
America 

Amorphous  bodies,  87 

Amplitude  of  vibration,  369 

Andes  Mountains,  209 

Animals,  autumn  influences 
upon,  29;  coverings  and 
warmth,  100;  cruelty  to,  345; 
habits  of,  after  eating,  186; 
joints  compared  with  man's 
145;  general  observations  on, 
for  November,  99  ;  move- 
ments of,  135;  movements  of, 
in  eating,  224;  winter  studies 
of,  1 80 

Angles,  of  incidence  and  reflec- 
tion, 277;  of  sun's  rays,  how 
to  measure,  62 


Annuals,  107 

Ants,  how  to  keep,  in  confine- 
ment, 75;  study  of,  397 

Apparatus,  care  in  preparing, 
108;  for  distillation,  84;  for 
fermentation,  46;  for  measur- 
ing angle  of  sun's  rays,  62; 
for  measuring  shadow,  61; 
for  astronomy,  61 ;  for  study 
of  light,  274;  for  study  of 
refraction,  320 

Appetite,  184 

Aquarium,  how  to  stock,  99; 
use  of,  and  how  to  make,  98 

Aqueous  agencies,  172 

Arms,   their  functions  in  man, 

139 

Areas,  means  for  studying,  68 
Astronomy,  apparatus  for,  61; 
charts  to  be  used,  52-60;  for 
April,  333;  for  December, 
166;  for  February,  246;  for 
January,  205;  for  June,  425; 
for  March,  289;  for  May,  381 ; 
most  important  conception 
in,  62;  for  November,  122; 
for  October,  90;  problems  in, 
205;  for  September,  61 
Atmospheric  agencies,  172; 
movements,  causes  of,  429 

BABY,  helplessness  of,  in  pre- 
hension, 221 

Bark,  study  of,  272 

Barometer,  position  of,  50; 
tube,  194 


439 


440 


INDEX. 


Batteries,  415-418 

Bees,  study  of,  396 

Beetles,  490 

Berries,  colors  of,  39 

Biennials,  107 

Birds,  flight  of,  136-140;  gen- 
eral observations,  September, 
32;  migration  of,  32-261; 
nests  and  eggs,  348;  nests, 
robbing  of,  345;  return  of, 
307;  study  for  October,  76; 
winter  residents,  99;  winter 
visitors,  99; 

Blanks  for  minerals,  177 

Bleaching  process,  421 

Blood,  coagulation  of,  265; 
circulation  of,  267;  constitu- 
tion of,  265 

Bloodvessels,  264 

Blue  flag,  318 

Boats,  pumping  leaky,  232 

Bogs,  339 

Boiled  egg,  experiment  with,  191 

Boiling  temperature,  84 

Bone,  study  of,  78 

Botany,  for  April,  312;  for 
December,  146;  drawings  and 
paintings  in,  36;  for  Febru- 
ary, 228;  for  January,  188; 
for  June,  403;  for  March,  269; 
for  May,  357;  mode  of  study, 
36;  use  of  key,  357;  for  Sep- 
tember, 36;  for  October,  81; 
for  November,  106 

Brain,  protection  of,  143 

Breadmaking,  184 

Breathing,  309 

Buds,  classified,  317;  develop- 
ment of,  in  spring,  315;  freez- 
ing of,  228;  unfolding  of, 
269-362 

Bunsen  burner,  115 

Burning  wood  to  illustrate 
chemical  change,  115 

Burrows  of  earthworms,  303; 
plugging  by  worms,  34 

Buttercup,  319 

Butterflies,  habits  of,  33 


CALCAREOUS  stones,  219 
Calendar,  natural  history,  261 
Cambrium  layer,  409 
Candle,  study  of,  375-377 
Capillaries,  264 
Capillarity,  232 

Carbon  dioxide,  243;  from  coal 
and  wood,  239,  240;  study  of, 

239 

Carbonic  acid  gas,  46 

Cardinal  points,  how  to  fix,  63 

Cartilage,  80 

Cat,  movements  of,  136 

Centre  of  curvature,  279;  of 
gravity,  150 

Cereals,  411 

Chapped  hands,  102 

Charcoal,  241 

Charts,  explanation  of,  52-54; 
use  of,  in  study  of  meteorol- 
ogy. 52 

Chemical  change,  47 

Chemistry,  for  April,  326;  for 
December,  159;  for  February, 
239;  for  June,  420;  for  Janu- 
ary, 197;"  for  March,  282;  for 
May,  375;  for  November, 
115;  for  September,  46;  for 
October,  86 

Chicken,  circulation  in  embryo, 
267;  development  of,  349 

Chlorine,  420 
!  Cider,  46 

!  Circulation,  262;  affected  by 
position  and  movements,  263; 
course  of,  264;  in  chicken  and 
frog,  in  embryo,  267 
I  Clay,  220;  amount  in  soils,  392; 
formation  of,  97;  models, 
burning  of,  257 

Climate,  conditions  of,  affect- 
ing character  of  food,  181; 
effect  of  coast-lines  on,  121; 
Euro-Asia,  293;  relation  of, 
to  thrift  of  a  people,  296; 
uniformity  of,  evidenced  by 
certain  plants,  269 

Clocks,  use  of,  196 


INDEX. 


441 


Clothing,  change  of,  105 

Clouds,  study  of,  50,  84 

Coagulation  of  blood,  265 

Coal,  history  of,  340;  origin  of, 
134-242;  study  of,  133-134. 

Coast-lines,  influence  of,  upon 
climate,  121 

Cocoons,  262 

Coke,  134 

Colors,  324;  natural  mode  of 
expression  for,  22;  relation  to 
absorption  of  heat,  no;  of 
fruits,  39;  of  spectrum,  43 

Compass,  44 

Concretions,  301 

Condensation,  84 

Conductors,  415;  of  heat,  154 

Conjunction,  superior  and  in- 
ferior, 292 

Cooking,  183 

Coral,  study  of,  298 

Cortex,  272 

Cow,  movements  of,  137 

Crawfish,  external  parts  of,  354; 
circulation  of,  268;  respira- 
tion of,  353;  study  of,  352 

Cruelty,  relation  of  science 
work  to,  4;  to  animals,  345 

Crystallization,  87 

Culms,  410 

Current,    electric,  direction   of, 

417 
Cuticle,  105 

DANDRUFF,  104 

Day,  length  of,  at  different 
places  compared,  247;  varia- 
tion in  length  of,  63 

Dew,  formation  of,  153 

Dip  of  magnetic  needle,  44 ;  of 
rocks,  70 

Disinfectants,  421;  charcoal,  241 

Dissepiments,  40 

Distillation,  84  ;  apparatus  for, 
84;  in  nature,  327 

Dog,  movements  of,  136 

Drainage,  91 

Drawing  compared  with  paint- 


ing, making,and  modeling,i8; 
difficulties  to  be  overcome,  19; 
function  of,  18;  use  of,  in  sci- 
ence work,  19;  when  properly 
commenced,  necessity  for,  22 

Duramen,  271 

Dust  in  air,  285 

EARTH,  movements  of  the,  167 

Earthworms,  burrows  of,  303; 
early  appearance  of,  303; 
casts  of,  304;  senses  of,  305; 
respiration  of,  314 

Eating,  number  of  times  a  day, 
186 

Ebullition,  83 

Echo,  373 

Egg-collecting,  and  directions 
for  preserving  and  labeling, 
346-348;  study  of  the,  349 

Electricity,  412  ;  direction  of 
currents  of,  417 

Embryo  chick,  349;  circulation 
shown,  267 

Endocarp,  40 

Endogens,  409 

Envelopes,  for  seeds,  30;  floral, 
361 

Epicarp,  40 

Equatorial  current,  432 

Equilibrium  of  bodies,  150 

Equinox,  vernal,  290 

Erosion,  94 

Euro-Asia  climate,  293;  produc- 
tions of,  336;  relief  and  drain- 
age, 248 

Evaporation,  83 

Evening  star,  207 

Exocarp,  40 

Exogens,  409 

Expansion  of  metals,  liquids, 
and  gases,  112-113,  154 

Experiments,  inaccuracy  of,  108 

Expression,  13;  correspondence 
to  modes  of  study,  14;  func- 
tion of,  14 ;  inappropriate 
modes  illustrated,  24;  relation 
to  art,  25 ;  necessity  of  combin- 


442 


INDEX. 


ing  different  modes,  20;  later 
stimuli  for,  21-25;  modes  of, 
enumerated,  14;  order  of  de- 
velopment of  the  various 
modes,  21 ;  peculiarity  of  each 
mode,  14;  place  of  the  various 
modes,  23;  pupil  to  choose  his 
own  mode  of,  24  ;  relation  to 
external  stimuli,  21  ;  relation 
to  modes  of  study,  13;  modes 
to  he  used  in  each  lesson,  28; 
earliest  stimuli  for,  21 

Extravagance  in  nature,  37 

Eye,  study  of,  354 

FAT,  study  of,  79 

Fauces,  pillars  of,  227 

Feathers,  arrangement  of,  100; 
study  of,  395 

Feet, 'position  of,  in  walking,  138 

Fermentation,  conditions  for, 
47;  apparatus  for, 46;  experi- 
ments in,  46 

Ferns,  363 

Fibrin,  how  to  prepare,  265 

Fibrous  minerals,  302 

Filtering  with  charcoal,  241 

Fish,  movements  of,  140 

Flame,  singing,  199-372;  study 
of,  375;  tests  for  minerals,  341 

Flames,  characteristic,  342 

Floral  envelopes,  361 

Flowers,  adhesion  and  cohesion 
in,  362;  complete  and  incom- 
plete, 360;  early,  319;  essen- 
tial organs  of,  361;  forms  of, 
362;  function  of  parts,  360; 
habitat  of,  359;  habits  of, 359; 
mode  of  study  for  children, 
357;  place  for  study  of,  in  bot- 
any, 357;  position  of,  361;  re- 
lation of,  to  fruit,  39;  visits  of 
insects  to,  360 

Focus,  conjugate,  279 

Fog,  formation  of,  84;  study  of, 
88-9 

Foliated  mineral,  302 

Food,  amount  needed,  184;  cli- 


mate affects  character  of,  181; 
cooking  of,  183 ;  of  insects, 
307;  mastication  of,  224;  pre- 
hension of,  221;  study  of,  181; 
times  of  taking,  186;  of  young 
birds,  394 

Form,  modes  of  expression 
for,  24 

Fossil  plants,  study  of,  251;  con- 
ditions of  their  production, 
252-6 

Fossils  defined,  214;  early  ideas 
concerning,  212  ;  meaning  of , 
212;  a  means  for  estimating 
ages,  217-218;  picturing  the 
necessary  conditions  for,  213; 
study  of,  212-218  ;  use  of  the 
study  of,  213 

Freezing,  effects  of,  173  ;  on 
plants,  146 

Friction,  producing  heat,  158 

Frictional  electricity,  412 

Frog,  circulation  in,  267;  devel- 
opment of,  308;  eggs,  308 

Frost,  study  of,  120 

Frozen  ground,  174 

Fruits,  colors  of,  39;  definition 
of,  39;  dried,  82;  function  of, 
37;  parts  developed  by  culti- 
vation, 40 ;  preyed  upon  by 
insects,  41;  relation  of,  to  the 
flower,  39;  stone,  41;  study 
of,  37 

Frying  meat,  184 

Fur,  hair,  82;  use  of,  101 

GALVANOMETER,  416 

Gas,  mode  of  collecting,  160 

Geese,  migration  of,  76 

Geodes,  301 

Geography,  for  April,  336;  de- 
fined, 64;  for  December,  168; 
for  February,  248;  for  Janu- 
ary, 209;  for  June,  428;  for 
March,  293;  for  May,  383; 
for  November,  124;  for  Octo- 
ber, 91;  for  September,  64; 
teach  with  history,  67 


INDEX. 


443 


Geolcgical  collections,  27,  68, 
69;  key,  74;  pictures,  297 

Geology,  for  April,  339;  for  De- 
cember, 172;  dynamical,  69; 
for  February,  251;  for  Jan- 
uary, 212;  for  June,  433;  for 
March,  297;  for  May,  386; 
conceptions  of,  68;  for  No- 
vember, 128;  for  October,  94; 
for  September,  68;  of  sur- 
rounding country,  69 

Germination  in  autumn,  38;  of 
seeds,  apparatus  for,  312; 
study  of,  313 

Gesture,  difficulties  in  teaching, 

15 

Geysers,  435 
Glacial  pebbles,  129 
Glands,  salivary,  226,  227 
Glumes,  410 

Great  Dismal  Swamp,  340 
Grapes,  color  of,  40 
Graphite,  134 
Grasses,  study  of,  410 
Gravel,  amount  in  soils,  391 
Gravity,   force  of,  how  to  find 

center  of,  150 
Growing  point,  316 
Gypsum  calcining,  257 

HAIR,  on  the  human  body, 
102-5;  m  tne  distribution  of 
seeds,  82 

Halos,  325 

Headache,  causes  of,  266 

Heat,  108;  capacity  for  experi- 
ments, 157;  central  thought 
of,  to  be  developed,  109;  con- 
duction of,  experiments,  154; 
conduction  of,  in  liquids,  156; 
convection  of,  155;  expan- 
sion, in;  as  a  force  in  melt- 
ing ice,  109;  produced  by 
friction,  158;  radiation,  ab- 
sorption, and  reflection,  109, 
no;  refraction  of,  157; 
sources  of,  158;  study  of,  for 
December,  152 


Hen's  egg,  study  of,  349 

Hepatica,  319;  habitat  of,  359 

Hibernation,  too,  261 

Horizon,  63 

Horse,  movements  of,  137 

House-fly,  399 

Hunger,  184 

Huxley,     Prof.,      on      science 

work,  6 
Hydrogen,     experiment     with, 

197-201 

ICE,  effects  of,  172 
Images,  278;  studied,  323 
Indian,  mode  of  walking,  139 
Inflorescence,  varieties  of,  359 
Insalivation,  226 
Insects,     collections     of,     307; 
coverings,  101;  habits  of,  32; 
how   to   collect,  31;   how   to 
mount,  307;   movements   of, 
34;    senses    of,    34;    visiting 
flowers,  360 
Insulators,  415 

Iron,  filings  combined  with  sul- 
phur, 118;  cast,  uses  of,  178; 
ore,  varieties  of,  176;  pig, 
178;  pyrites,  343 

JACK-IN-THE-PULPIT,  318 
Joints,   study    of,   80;    in    man, 

145 
Jupiter,  382;  study  of,  291 

LAKES,  heating  of  water  in,  156; 

effects  on  storms,  332 
Language,    15;    compared,    20; 

data  for,  20;  difficulties  to  be 

overcome,  20,  23;  use  of,   in 

science  work,  19 
Latitude,  65 
Larvae,  care  of,  75 
Leaves,     compound,     408;    the 

prey  of  insects,  38;  study  of, 

406 

Lenses,  study  of,  322 
Lenticels,  272 


444 


INDEX. 


Lessons,  field,  data  gathered 
in,  388;  directions  for  con- 
ducting, 386;  plan  for,  27 

Lever,  classes  of,  147,  148; 
study  of,  147 

Levers  found  in  the  body,  149 

Liber,  272 

Life,  plasticity  of,  64 

Ligaments,  80 

Light,  42;  apparatus  for  study 
of,  274;  different  rays  of,  277; 
experiments  with,  274;  modes 
of  darkening  room  for  study 
of,  274;  necessity  for  clear 
conceptions,  274;  study  of  re- 
fraction, 320 

Lightning,  415 

Lily,  318 

Limbs,  relative  strength  of,  144 

Lime-water,  116 

Limestone,  219;  calcining,  257 

Liquefaction  experiments,  153 

Liquids,  buoyancy  of,  234;  pre- 
hension of,  223;  pressure  of, 
236;  expansion  of,  112 

Litmus  paper,  344 

Locomotion,  136 

Lodicules,  410 

Longitude,  65 

Luminous  bodies,  276 

Lyell's  Principles  of  Geology, 
213 

MAGNET  in  study  of  minerals,  72 
Magnetic  needle,  declination  of, 

44;  dip  of,  44;  how  to  make, 

43;    pole,  44 
Magnetism,  43-412 
Magnum  foramen,  142;  making, 

l6;as    a    stimulus,    23;  when 

properly  commenced,   22 
Map-making,  65 
Maps,  Signal  Service,  52 
Marble,  effect  of  acid  upon,  117 
Marrow,  78 
Marshes,  study  of,   70 
Mastication  of  food,  224 
Meal,  full,  before  retiring,  187 


Measurements  in  field  lessons, 
388 

Meat,  lean,  183 

Medullary  rays,  272 

Mercury,  a  morning  star,  427; 
capillarity  of,  233;  experi- 
ments with,  194;  evening 
star,  335;  compared  with  Ve 
nus,  246 

Mesocarp,  40 

Metals,  expansion  of,  112-154 

Meteorology,  for  April,  330; 
charts,  52-60;  for  December, 
163;  for  February,  244;  gener- 
al directions  for,  48-54;  for 
January,  202;  for  June,  422; 
for  March,  286,  for  May,  378; 
for  November,  120;  for  Octo- 
ber, 88;  for  .September,  48; 
times  for  observation,  49 

Meteorological  records,  48,  49, 
205 

Microscope,  compound,  266 

Minerals,  blanks  for,  177; 
forms  of,  301;  fusibility  of, 
342;  of  North  America,  170; 
physical  properties  of,  71 

Mineralogy,  for  April,  341;  for 
December,  176;  for  February, 
257;  for  January,  219;  for 
June,  436;  for  March,  301; 
for  May,  390;  for  November, 
133;  for  October,  97;  for  Sep- 
tember, 71 

Mineralogical  record,  73;  how 
to  make,  72 

Mirrors,  277;  axis  of,  279 

Mixture,  illustrated  by  sulphur 
and  iron  filings,  118 

Modeling,  17;  necessity  for,  22; 
use  in  science  work,  17-18 

Moon,  the,  123;  full,  90;  phases 
of  the,  50;  rings  of  the,  325 

Morning  star,  207 

Mosses,  study  of,  364 

Mountain  peaks,  temperature 
of,  157 

Mountains,   effects  of,  on  pro- 


INDEX. 


445 


ductions,      337;      effects      on 
storms,   165;    influence  upon 
climate,  88 
Muscle,  study  of,  77 
Music,  15;  and  noise,  373 

NAILS,  care  of,  104 

Natural  History  Calendar,  261 

Near-sightedness,  355 

Negative  electricity,  414 

Nests,  mounting  birds',  346; 
preservation  of,  346;  for  in- 
sects, 31 

Neutral  equilibrium,  151 

Nitrogen,  282; 

Nodes  on  plant  sterns,  317;  on 
strings,  vibrating,  371 

Non-conductor,  415 

Noon-marks,  use  of,  206 

Normal,  the,  277,321 

North  America  and  Europe, 
contrasts  in  climate,  432;  cli- 
mate of,  124;  drainage  of, 
91;  position  of,  etc.,  67;  rain- 
fall of,  124-126;  relation  of 
its  geography  to  history,  92- 
93;  soil  and  productions  of, 
168 

North  pole,  magnetic,  44;  alti- 
tude of  sun,  334 

OIL  on  the  skin,  102 
Onion,  318 
Oral  sounds,  21 
Organs,  essential,  361 
Organic  agencies,  297 
Oscillation,  195 

Oxygen,  experiments  with,  160- 
161 ;  preparation  of,  159 

PAINTING  compared  with  model- 
ing and  making,  18 

Pans  for  germination  of  seeds, 
312 

Papillae  of  tongue,  182 

Peat,  134;  swamps,  340 

Pebbles,  study  of,  128;  formed 
by  glaciers,  129 


Pencil  placed  in  water,  321 

Pendulum,  195;  arc  of,  196; 
different  forms  of,  196 

Penumbra,  281 

Perennials,  107 

Pericarp,  40 

Perimysium,  77 

Perspiration,  103 

Phosphorus,  282 

Physical  change,  1 15,  116;  prop- 
erties of  minerals,  71 

Physics,  for  April,  320;  for  Feb- 
ruary, 230;  interest  in  exper- 
iments, 42;  for  January,  189; 
most  important  conception 
of,  42;  for  Mafch,  274;  for 
November,  108;  relation  to 
other  studies,  42;  for  Decem- 
ber, 147;  for  June,  412;  for 
May,  366;  for  October,  83; 
for  September,  42 

Pig-iron,  178 

Pillars,  clay-capped,  94 

Pine  trees,  229 

Pistil,  361 

Pith,  271 

Placenta,  40 

Planets,  positions  of,  292;  rela- 
tive distances  from  the  sun, 
61 

Plant-life,  cycle  of,  36;  changes 
in,  38;  lice,  398;  preparation 
for  winter,  106;  reproduction 
of,  1 06 

Plant  axis,  underground  forms 
of,  318 

Plants,  composition  of,  403, 
geologic  effects  of,  339; 
growth  of,  38;  shapes  of,  270; 
water-culture,  404;  witnesses 
to  uniformity  of  climate,  269 

Plumbago,  134 

Pneumatic  trough,  159 

Poison-bottles,  31,  306 
Pole,  balancing,   152 
Poles  of  magnetic  needle,  44 
Pollen,  361 
Polyps,  coral,   299 


446 


INDEX. 


Positive  electricity,  414 

Potato,  318 

Pond  life,  308 

Prickles  and    hooks    on    seeds, 

37 
Prism,  324;  mode    of   making, 

43 

Pulse  at  different  ages,  266 
Pump,  how  to  make  a,  230 
Pumping  leaky  boats,  232 
Pyrites,  iron,  343 

BUARRIES,  173 
uartz,  220 

RABBIT,  movements  of,  137 

Radiation,  109 

Radiators  and  reflectors,  no 

Rain,  effects  on  surface,  94 

Rainbow,  325 

Raindrop,  history  of,  84 

Rainfall,  effects  upon  soils,  438 

Rain-guage,  51 

Rain-water,  what  becomes  of  it, 

433 

Rapids,  how  formed,  95 
Rays  of  light,  277 
Reading,  354 

Reflection,  109;  angle  of,  277 
Refraction     of     heat,     157;    of 

light,  320 

Region,  how  to  study  a,  69,  70 
Reptiles,  2|.oo 
Respiration,  309-314,  353 
Rocks,  dip  of,  70 
Root  compared  with  stem,  319 
Roots,  316;  aerial,  319 
Rope-walkers,  152 

SALIVA,  uses  of,  226 
Salivary  glands,  226 
Salt  in  water,  tests  for,  328 
Sand    in    soils,   392;    study   of, 

97 

Sarcocarp,  40 
Scales   of   fishes   and    reptiles, 

101 
Science  record,  54;  work,  23 


Season,  influence  upon  animals, 
30 

Sealing-wax,  to  electrify,  413 

Sedimentation,  94 

Sediment  in  stream's  course, 
95 

Seeds,  collections  of,  81;  dis- 
tribution of,  82;  effects  of 
early  growth  on,  37;  freezing 
of,  146;  germination  of,  37, 
312;  study  of,  314 

Seeing,   275-354 

Sensation,  104 

Shadow,  how  to  measure,  61 

Shadows,  280 

Shoes,  improper  forms  of,  139 

Shrubs,  271 

Signal  service,  for  April,  331; 
for  December,  164;  for  Febru- 
ary, 244;  instruction,  51;  for 
January,  203;  for  June,  423; 
for  March,  288;  maps,  52;  for 
May,  379;  for  November, 
121;  for  October,  89;  officer, 
52;  for  September,  55 

Silicious  stones,  220;  effects  of 
burning,  258 

Silver  nitrate,  328 

Simmering,  83 

Singing  flame,  199-372 

Siphon,  the,  231 

Skeleton,  the,  140 

Skin,  the,  102-104 

Skull,  human,  142 

Slopes  of  South  America,  126, 
127 

Smell,  sense  of,  181 

Snakes,  401 

Snowfall,  163 

Soap  solution,  327 

Soft  water,  327 

Soils,  absorption  of  heat,  437; 
adaptation  to  vegetation,  438; 
water  held  in,  436;  effects  of 
winds  upon,  438;  evapora- 
tion from,  437;  formation  of, 
97;  study  of,  390-393;  study 
of  properties,  436 


INDEX. 


447 


Solids,  prehension  of,  223 

Solomon's  seal,  318 

Solstice,  summer,  426;  winter, 
1 66 

Solution,  86 

Sori,  364 

Sound,  rate  of  speed,  373;  re- 
flection of,  373;  location  of, 
374;  study  of,  366;  vibrations, 

374 
South    America,    climate,    170; 

climatic       conditions,       210; 

drainage,      126;     forest    area 

of,  210;  productions  of,   209; 

slopes  of,  126,  127 
Specific   gravity,    133;    how    to 

find,  235 
Spectrum,  43 
Spiders,    398;     circulation     of, 

268 

Spike,  410 
Spores,  364 

Spring,  early  signs  of,  289 
Springs,  388;  intermittent,  434; 

study  of,  433 

Squirrel,  movements  of,  138 
Stable  equilibrium,  151 
Stalactite,  302 
Stalagmite,  302 
Stamens,  361 
Steel,  uses  of,  179 
Stem,  compared  with  root,  319 
Stems,    forms   of,    270;    under- 
ground, 318 
Stone  fruits,  41 
Stones,    calcareous,    219;    frost 

action,  175 
Stratification    70 
Stratified  rocks,  302 
Stream,  its  swiftness,  95 
Strike  of  rocks,  70 
Sublimation,  343 
Suction,  189 

Sulphur  and  iron  filings,  118 
Summer    rains,    422;     solstice, 

426 

Sun's  rays,  angle  of,  62 
Swallowing,  226 


!   Swamp,  Great  Dismal,  340 
Swamps,  study  of,  339 
Symbols,  function  of,  333;  use 

of,  122 
Synovial  fluid,  88 

TADPOLES,  35,  308;   circul?tion 

of,  267 
Taproot,  319 
Taste,  sense  of,  181 
Tears,  356 
Teeth,  study  of,  225 
Temperature,     contrasts,     124- 

126;    mode   of  study  of,  in; 

region  of  lowest,  121;  sense, 

109 

Tendon,  77 
Tests    for   carbon  dioxide,  47; 

flame  for  minerals,   341;    for 

impure  air,  311;  for  purity  of 

water,  326;  for  salt  in  water, 

328;  for  temperature,  in 
Thawing,  effects  of,  173 
Thermometer,  position  of,  50 
Thunderstorms,  422 
Time,  estimates  of,  217,  218;  for 

observations,  49;  of  day,  62; 

importance  of,  130 
Tissue,  adipose,  79;  connective, 

78;  material  for  study  of,  76,77 
!    Tongue,  186-226 
I   Tones,  study  of,  368;    pitch  of, 

370 
|    Tonsils,  227 

Touch,  sense  of,  105 
!   Trade-winds,  429,  430 
i    Training,  importance  of,  222 
Trunk,  the,   140;  the  flexibility 

of,  143 

Tufa,  302;  formation  of,  435 
Turtles,  400,    402;   hibernation 

of,  100 
Twigs,  changes  of,   38;  growth 

of,  313 
Twilight,  382 

UMBRA,  281 

Units  of  measurement,  68 


448 


INDEX. 


Unstable  equilibrium,  151 

VALVES  in  veins,  264 

Vapor,  84 

Variation,  of  day's  length,  206 

Veins,  264 

Venation  of  leaves,  407 

Venus,  207,  382;  compared  with 

Mercury,  246 
Ventilation,  153;  311 
Vernation  of  leaves,  363 
Vertical  rays,  effects  of,  429 
Vibrations,    study   of,   369-377; 

time  of,  195 
Vinegar,  118 
Voltaic  electricity,  415 

WALKING,  habit  of  Indian  in, 
139;  position  of  feet  in,  138 

Water,  hard  and  soft,  327;  im- 
purities in,  326;  effect  of 
boiling,  327,  328;  effects  of, 
in  pebble-making,  128;  study 
of,  326;  contains  sand  and 
silt,  128 

Waterfalls,  how  formed,  95 

Water-newts,  267 

Weathering  of  rock,  97 


Weather,  effects  on  plants,  39 

Webs  of  spiders,  398 

Wells,  study  of,  433 

Wind,  determining  direction  of, 

44;   effects    upon    soils,    438; 

effects  upon   land  and  water, 

430;   study  of   428;  variable, 

430 
Winter,  condition  of  plants  in, 

188;      condition      of      living 

things  in,  135 
Wood,  burning  of,  115;  formed 

in  one  year,  81 ;  rings  in ,  271 ; 

study  of,  271 
Worms,  burrows  of,  303;  habits 

of.  34 

YEAST,  46 
Yellowstone  Park,  435 

ZERO  isotherm,  245 

Zoology,  for  April,  303;  for  De- 
cember, 135;  for  February, 
221;  for  January,  180;  for 
June,  394;  for  March,  259; 
for  May,  345;  for  November, 
98;  for  October,  75;  for  Sep- 
tember, 29 


14  DAY  USE 

RETURN  TO  DESK  FROM  WHICH  BORROWED 

EDUCATION-PSYCHOLOGY 
LIBRARY 

This  book  is  due  on  the  last  date  stamped  below,  or 

on  the  date  to  which  renewed. 
Renewed  books  are  subject  to  immediate  recall. 


64: 


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MAY  2  9  REC'D 


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LD  21A-30m-6,'67 
(H2472slO)476 


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UNIVERSITY  OF  CALIFORNIA  LIBRARY 


